This severely limits the use case of addons, in some situations configurable options are not ideal so the use of an addon works better such as a license tied to a particular service the addon is being added to.

In my case I require per user licensing tied to a service so the ability to add a user license for a particular feature to the main service is much better as an addon as customers can see all the extra licenses they are buying rather than being bundled into a single line item and it also improves the signup experience as they are not presented with 20 different config options for all possible licenses with very little detail about each.