sv_allowexit "0" still allows exit in cooperative gamemode
Created attachment 567 [details] cfg and wad to replicate the situation. sv_allowexit "0" does not prevent players from exiting the level with sv_gametype "0" (coop) set. I was playing with the idea of a cmat-deh.wad sandbox server with the shotgunner for target practice and stumbled on this block. Ideally players should not be able to exit the level and instead die from the sv_fragexitswitch "1" setting, which is what happens with sv_gametype set to "1" (dm).
sv_allowexit's main function is to kill any player trying to exit in competitive gamemodes. Since Odamex has no real support for ACS-based exits, I highly doubt this won't be implemented for now...