Two DMs in VTT

I made the mistake of getting a group of 9 close friends as players. It has been boring for them and stressful for me. It would be a big favor if the Maps VTT had the capability to have two DM permission accounts in one campain

Best you can do is have the other potential DM set up their own campaign and have everyone leave one to join the other when the time comes. Whoever's providing content sharing (if any) can either activate it on the second campaign as needed or switch it to that campaign.