How hard is it to support a freemium model? Lower fee plan from Apple that allows external payments, no enterprise support, no App Store promotion, limited iOS

How hard is it to support a freemium model? Lower fee plan from Apple that allows external payments, no enterprise support, no App Store promotion, limited iOS API access (nothing sensitive), etc. Higher fee plan to give developers access to more sensitive APIs and Apple payments, etc. Mark the latter apps as “supported by Apple” or something in the store. I know it doesn’t solve everything but it’s better than the current state of things.