Yeah, of course it is on a "what if" level, something worth keeping a second gear set for.
Not gonna be something you can and/or will do every fight, but it is something to keep in mind and having an extra gear set would not hurt since I figure there will be several possiblities for this in SoO. From what I heard SoO fights got a lot of adds.
However, look at ToT. There are a lot of fights where you can create those opportunities.
Jin-Rokh: ~Meh~ You can pull some of the trash here to the boss and keep them on you but this trash is not really that great.
Horridon: ~Meh~ Some of the mobs dont really do much so you can keep them alive on the tank, there is also the possibility of pulling the snake adds infront of horridon.
Council: ~Okay~ Other than that you have multiple bosses there are a lot of trash that is friendly enough to be pulled to the boss without causing harm
Tortos: ~Insane~ Bats. Bats. Bats.
Megaera: ~Insane~ Shale Stalkers, need I say more
Ji-Kun: Nothing I can think of
Durumu: Nothing I can think of
Primordius: ~Great~ Trash trash trash
Dark Animus: ~Great~ The boss already includes multiple adds
Iron Qon: ~Insane~ You can just pull two or three spider packs to the boss, they tend to die though so your raid needs to be careful with cleaves and shit
Twins: ~Insane~ Pull spiders from Iron Qon and profit
Lei-Shen: ~Great~ I always spawn adds intentionally from the bouncing bolts, those adds really does not do shit and just give tanks GC procs, with this change, just spawn 6-8 adds every transition and keep them on the tank.
The only fight that really inherantly had the AE element in ToT was Tortos and maybe Animus, but with some clever use of trash you can make absolutely insane use of it on atleast half the fights.
So looking at that, I would probably have used a standard gear set for
Jin-Rokh, Horridon, Council, Ji-Kun and Durumu
Maybe abusing avoidance on Jin, Hor and Counc for rankings but not for progress.
For Twins, Iron Qon and Prim I would probably also have used a standard gear set simply because you can pull enough small adds to get constant GC procs even without extra dodge or parry, and the adds hit for shit.
I would probably experiment on the other fights, going full avoidance on atleast Tortos and Megaera with all those adds.
For animus and LS I would probably have experimented between avoidance for GC procs and haste. On LS the adds does not really hit for much so probably haste build, avoidance build would have looked interesting for Animus.