In my experience it hasn’t been a VFX decision to use LiveGrain, it’s been a production company decision upstream when steering director/dp away from shooting film.
Our preferred workflow (no in-house color); the colorist sets the grade and grain look, shares the grain config which we apply and render post vfx, before delivery.
I’m not sure that we’d use LiveGrain to sell a look to the client once it has reached a Flame suite. Furnace ReGrain ftw.

ah so its a expensive OFX plugin.
Cool. lol
can we make this a new feature request?