[Bacardi]

I do not understand your problem.

- autoexec.cfg only work once when you launch your server, server do not exec that file later on.
- use one collection at time.
If you want change collection to another, use server commands (host_workshop_collection xxxxxx), be patient between map change.

- you can look mapgroup map list with server command, rcon print_mapgroup_sv

- You can disable csgo end match map vote mp_endmatch_votenextmap 0 in your gamemode_*_server.cfg file
You still see "map voting" but players can't vote. It just show few maps in cycle.