I advice people to go to the IRC Chat, since many changes are being done, only when I find a stable solution I will post more details about the configs. till then you can try to "work" with the "buggy" version.
since the multiple mechanism it's still not perfect if you want to run non-stop refs for now.
I advice the following.
create 1 rooms.ini for each group of vms you want and set the rooms.ini in the local path for this group of vms so each group go to their own rooms.ini
Group 1 , 6 vms -> rooms1.ini
Group 2 , 6 vms -> rooms2.ini
Group 3 , 6 vms -> rooms3.ini
then I recommend to use randomwin=0 (what is default now)
minigame=1 could save some resources but also not sure about afk warnings.
This is not the way i want it to work in future but seams the way it works atm without stopping.