Joe_Lurie MS blocked all store controls on Windows 11 for private store. The moment you make GPO's or Configuration Profile require private store only, it's all over donkey kong.
This has been the biggest issue as MS (As you say) have not yet released an enterprise store, has blocked everything for Windows 11.
The only workaround we've found so far is to download each and every APPX from the private store and then to re-upload them into MEM. The big headache for us is that they no longer remain updated, we have to periodically check for updates. Further due to this change, apps that once worked in user mode, don't.
So self service items are all dead. This was wonderful in the Private Store as users could easily do self service and install apps. Company Portal is not an equivilency.
Working with private software vendors is the easy part. Getting automatic updates no longer works (as detailed above). The hardest ones are items that are mostly MS Apps themselves where you need the APPX.