Since we're not likely to get to equip 3 legendaries for months, I'm assuming if you were blessed by the RNG gods and got your MS's 2 BiS legendaries, the logical choice would be to change your loot spec to OS and work on that?
Or do you think it makes sense to try to squeeze out the 3rd and have it ready for 3 legendary equips?
I'd be interested to hear what more hardcore players are doing.