I understand the rationale, thanks.
But the current decision have the following disadvantages, from what I see:
it ignores my settings - I'm asked at which domain I would like Synapse to be installed and then I get it on my root domain, regardless my input - I've spend quite a time to figure that out
you are dependant on the ever growing list of new domains
What we discuss calls delegation in Synapse terminology. It feels like extra feature for me and I really can't see reason to keep in on Cloudron, at least not with current setup.
Just in case - I know how to make things working for me, so I would be just fine with things as is, but I believe it's wrong from the logical perspective.