I'll FLS hunting rounds, or any other rounds that I do not want feeding issues with, I would do it for comp rounds as well.
I usually neck new brass the first two times to let the brass fill out to full length before I set up the FLS die on it, and to make sure neck tension is set where I want it, as I'll mandrel it to size.
I usually only neck rounds past 2nd rd for my falling blocks, as they're the ones I put the most rounds thru, but, still FLS at the 4-5rd mark. There were times when I'd use 400-600 rds on a weekend, first 200 load during the week, then another 200 Sat nite, maybe 200 Sunday nite. Had to neck them for the time factor. I even used a Lee handpress doing that, if they were due for FLS, use the RC during the week.
Also have bushing neck only/bump dies, haven't loaded a mass amount with them, but, it's a nice option, seems to work OK, all I have to worry about is case body dia with them.
And you have to remember the lower case and the shoulder do harden with firing and lose elasticity, they want to spring back to fired size, so, somewhere along the line, you have to FLS to take care of those two, annealing won't help with the lower end.