Managed Apple IDs in ABM & Domains that are LOCKED

Hi Team

We setup ABM and linked it to a company domain name called xyz.com and then we had MANAGED APPLE IDs . where test users were given firstname.surname@xyz.com. when we added the domain name into ABM, we were given 30 days which has passed.

We then identifed through testing that there were a number of practical limitations with using MANAGED IDs and we should have just used personal apple IDs using the company email address but just not locked the domain.

We now want to unlock/remove the domain that is locked, but speaking to ABM support they say it CANNOT be done but i can find lots of articles saying it can be and from the Apple ABM support website there are specific instructions to remove a domain.

Remove a domain in Apple Business Manager – Apple Support (UK)

CAN ANYONE CLEARLY CONFIRM THAT WE CAN JUST REMOVE THE DOMAIN NAME SO THAT WE CAN THEN JUST ALLOW OUR USERS TO MAKE APPLE IDS FOR THEIR DEVICES USING firstname.surname@xyz.com

We do not care if we have to delete the test managed apple IDs.

This is a trial so we can then get on with enrolling a total of 60 users with their devices in supervised mode and allow them to use any APPLE ID (whether it is in the form of @xyz.com or @gmail.com

A really clear and definitive answer would be really helpful. We can't believe that once a domain has been added it REMAINS locked FOREVER.

Thanks in advance