Multiple devices Garmin Explore account

I have two InReach devices on my Garmin Explore account - one added 9 years ago and one added 7 years ago. I just purchased an InReach Mini 2 and see that I cannot add it to my existing account but need to establish a new account for that device. OK, I understand that although it seems like an unnecessary pain in the butt.

I also read on the Garmin site that with multiple devices on a nonprofessional account, only one can be active at a time. I believe my account is a "legacy" account, and I want to make sure that each device can actually be active at the same time since I have never been aware of this limitation.

Thanks