Was also thinking about in which scenarios it would be worth reforging the rating with higher amount on an item despite its RSV-value being higher then the rating with lower amount on the item.

RFlow = reforge the low (and weaker) stat
RFhigh= reforge the high (and stronger) stat

We want to find when:
RFlow < RFhigh

high * RSVhigh + low * RSVlow * 0,6 + low *0,4 * RSVMastery < high * 0,6 * RSVhigh + high *0,4 * RSVMastery + low * RSVlow

This can be simplified to:

RSVMastery > (high * RSVhigh - low * RSVlow) / (high – low)

or (where diff = high - low)

RSVMastery > (low *(RSVhigh - RSVlow) + diff * RSVhigh) / diff


This equation don't make us much more enlightened though. Plugging in some reasonable numbers might give us a little info.
Using high = 110, low = 100, RSVhigh = 1,41 and RSVlow = 1,37 as in your example gives that if RSVMastery > 1,81 its still worth reforging crit for you. However doing the "wrong" reforge is about 1 dps difference if RSVMastery = 2,13.

Increasing only the RSVhigh to 1,47 and using same numbers for the rest, gives RSVMastery > 2,47 for it to be worth reforging the better stat. The difference between the 2 alternatives are still less then 2 dps though. Bumping the RSVhigh to 1,57 gives RSVMastery > 3,57 to brake even and penalty for doing it wrong to 5dps.

To conclude it is depending on a lot of factors, but unless they are pretty close in value reforging the weak stat is likely the best. But making the wrong decision isn't a catastrophe.