Let’s say I build an app and sell it to someone. I would need to have a way to transfer ownership of this one app (not the whole account) to a third party. Ideally like this:

My account before sale (including 3 apps as in Tier 1):
1 App with production app to be sold (non-subscription)
2 Unused apps (non-subscription)

After the sale to third party account:

My account:
3 Unused apps (non-subscription)

Account of third party after sale:
1 transferred production app (regular subscription plan), decoupled from my account