Not sure if this is already posted anywhere, but I found this addon tonight and have found myself pretty happy with it.
Bang! Libram Swap
What it does is you set it so it will replace
[Libram of Mending] with
[Libram of Souls Redeemed] or others once you receive the buff from Mending. Then it switches back to it as the buff nears it's end(you can set the amount of seconds of remaining duration before switching). So essentially, (assuming you're casting Holy Light at least once every thirty seconds, which I hope you are) you are gaining a static 22mp5 without losing the hps you could have gained from RoSD by leaving Mending equipped the whole time. Now obviously this can also be done manually, but this mod saves you the clicks, because we're busy as it is.