hi there, with the statement obove from the official forums in mind, we can start to think about how we could influence our rotation to provide the most possible time for autoshot to proc our t12 4pc. I dont know numbers about a possible ICD on the 4pc, but it will likely be good to cast cobra still we near cap focus in hope we get a proc without waste focus or delay KC. If so we have to balance our overflowing focus

Moreover the 4 pc will help the useage of our BW to simple cast KC and ArcS. In dependence of the power from the 4pc I imagine a we use fevor more rarely

So then do you recommend using FF every time it is off of CD and not waiting for frenzy to proc?

By the time FF comes off CD, as long as your pets been on the boss, it'll have 5 frenzy stacks and you'll have maybe 3s of FF downtime. If your pet hasn't had 100% boss uptime than depending on how much time you have left on your current FF and how many Frenzy stacks your pet has, it could be worth using FF without 5 Frenzies.

There's prolly more mathcrafting than this though.

Yes, unless your pet is being kept out of the fight for extended periods (in which case you should review whether you should be BM for the specific fight) you should always have 5 stacks of frenzy when FF comes off CD, the only exception being the beginning of a fight. My advice for the beginning of the fight is to let your pet get to the boss while you apply SrS and get in position if you are not ahead of time, then pop MD (to the first tank) and BW for KC and AS spam for the duration. By the time you have spent your BW your pet should be at 4 or 5 stacks of frenzy (depending on how fast you acted) and therefore good to go for FF. Personally I keep FF macroed to CoS (ahead of the shot), so I automatically use it whenever its off CD.
The premise is of course that you are hitcapped, and thus your pet is hitcapped.

Am I missing something here? Wouldn't this cause FF to consume whatever stacked Frenzy (1 to 5) your pet has at the time FF comes off cooldown (instead of consuming a full stack of 5 if you wait for it?) If so, why is that a good thing?

BW is our big damage increasing cooldown, as such we lose damage output if we lose applications over a fight. The way you describe your usage leads me to believe that you haven't actually read BW and Frenzy;
Bestial Wrath increases damage done by your pet by 20% for 10 seconds. Frenzy gives your pet a stacking buff every 3 seconds (every basic attack) for a total of 30% attack speed increase at 5 stcaks. This attack speed increase for the pet only affects its autoattacks. There is no argument that having 5 stacks of frenzy on your pet during a BW is more bang for the buck than having 0, but the actual real world damage increase is negligable and will translate to 1-2 extra pet autoattacks that gain 20% damage. Comparing the actual gain from only using BW with full frenzy to delaying BW to be at full frenzy can easily cause you to lose out on a BW over the course of a fight. Add to this that the only time in a fight you will be guaranteed to not have any frenzy stacks for FF is the beginning of the fight there really is no good reason to not start with BW, especially if you are MD'ing to the tank (as you should be unless you have been specifically told otherwise) for more threat transfer.

Yes it causes FF to consume frenzy whenever its off CD, but as full Frenzy merely causes twice the attack speed increase on the pet as it does on you (6% on pet per stack and 3% on you per stack consumed) it is a wash for autoattack/autoshot damage, but on the hunter it also increases casttime shot speed.
Having said that - as I said in my last post - unless your pet is consistently not on the boss or it is missing (which it should not) it will have built up a 5 stack every time FF comes off CD - it takes 12 seconds from the first stack to the fifth as there are 3 seconds bewteen basic attacks, or a total of 15 seconds from reaching 5 stacks, to being back at 5 stacks if you fire off FF between the 5th and "6th" stack. FF has a CD of 15 seconds, so regardless of when you use it, there will be 5 pet basic attacks before it comes off cooldown again. The proc effect in the UI doesn't trigger till the 6th stack would have applied unfortunately, so using FF manually on the proc will consistently leave you with up to 3 seconds of non hasted time and a wasted stack of frenzy, this can really add up over the course of a fight.
Macroing FF to CoS does have the potential to loose you a little haste if you have to move or your pet is stunned (like on Halfus), but overall, as I started this answer with, the application of the haste to you or your pet is a wash, if not a slight gain when on you due to interaction with CT shots (CoS).

I had too come the realisation after sleeping on it that actually waiting for the 5 stacks before popping TBW could possibly be a DPS loss. In an actual raid situation when i think back to previous runs as BM i only had to wait a few seconds, 3-5 at max, and i could have popped TBW sooner and gaining the 5 stacks DURING TBW with no risk of possibly losing a TBW CD over the course of a fight.

With regards to the waiting for FF i think i made it confusing so apologies. When FF falls off AND there is no TBW anytime soon i just make sure i have some focus to cast a few AS and/or FB till FF is at full stack and i am ready to start spamming 3xCoS and an arcane between FB's again. Using FF before having 5 stacks of frenzy is not needed with good focus preparation thus macroing it into CoS i can only see as a DPS loss once a fight is in full flow.

Ignoring the exact analysis of whether or not 3% hunter haste for 15 seconds is worth more than having 15% haste 3 seconds earlier, I would like to point out two errors in the above.

One, FF lights up as soon as your pet gets 5 stacks of Frenzy; there is no 3 second/basic attack delay.

Second, the following macro

/cast Focus Fire
/cast Cobra Shot

does not trigger FF reliably. I've seen multiple CS go off with the FF lit up and off cooldown.

(One more thing -- Frenzy apparently doesn't stack when your pet makes a Glancing Blow. That's the only reason I can think of as to why I don't see Frenzy uptime in excess of 75% or so on, e.g., Argaloth.)

Up on testing i can confirm it does light up immediately upon 5 stacks so no wasted time.

Also the macro can still work though with the right amount of haste. I have 1826 haste rating atm and 5xFrenzy effect just refreshes in time to use FF off CD on a dummy. In a raid with the 10% haste buff too you certainly would not need the amount of haste i have to make it work.

With regards to the macro not working you just need to fire an instant as FF comes off CD to make it work otherwise it will continue to use CoS without using FF for some reason.

The only prob i see now is during RF as using FF and RF together would bring your CoS cast time to <1sec and thus a waste of haste. I suppose that could be easily fixed with putting an unmacro'd CoS somewhere on my bars, if it is even really worth bothering about.

Regarding FF lighting up, I will admit I haven't checked lately, but it went live with the issue that I refer to. If it lights up on 5 stacks, good. I am not sure why you are talking about haste, haste does not affect pet basic attacks, and therefore does not affect the buildup of frenzy stacks or the cooldown of FF. It is not necessary to macro FF into an instant, a basic macro in CoS means you use it before CoS if it is off CD, and you leave it on the pet while you are not using any Cast Time shots.
1826 haste rating is a lot more than is useful for BM because we don't really want to increase the amount of CoS we fire, but the amount of AS (by way of generating more focus) - it is, of course, because you are MM optimized(?) and have focused on reforging to haste, but still a lot of "wasted" haste - FF and RF should not bring you under 1 second CoS, and only does so because you have so much haste. With 4t11 bonus, RF and FF you need 11.8% haste from gear to hit 1 second CoS. To hit 1 second CoS without FF requires 28.57% haste from gear, or twice what you have now, so using FF during RF, even with the very high amount of haste optimized for MM is a gain, even if the final cast time ends up at 0.978 seconds.
Conclusively, even MM optimized 4t11 characters should keep FF up, even during RF (however, as always, stagger RF and Blood Lust).

It's been like this for a long time (the whole of WotLK at least) when trying to use a non-GCD ability/item in a macro that has a spell that can be queued. You are right that if you spam Cobra Shot non-stop it will not activate FF ever. Wait until the cast bar reaches the very end for the cast you want FF to be activated. This will introduce at least 1xYourLatency into your rotation every time it goes up, but this is fine because there's really no practical faster way to do it.