Separating VR players from the main ARMA playerbase is a worst mistake you could make. There is not gonna be enough players to populate 1 big battle. The most popular VR shooter Pavlov have something like 10 half empty servers.
I'm over 30 y/o, working at a factory 12h a day, i'm not doing that shit. In most VR shooters you have an option to crouch with a button press. It's always an option for the people who want to roleplay. Like me, then i'm not tired.
Just add the option for VR people to create their own VR-only servers. Most of VR players are still gonna play on "flat" servers because most ARMA players have friends who don't own VR. Better play with slight disadvantage than trying to have fun on almost empty server.