You can still structure the IAPs to account for that, no? There's nothing stopping you from creating arbitrary bundles of IAPs, and pricing those bundles separa

You can still structure the IAPs to account for that, no? There's nothing stopping you from creating arbitrary bundles of IAPs, and pricing those bundles separately. One's an upgrade and presented to people who've already bought the last version, another's for new users, and priced higher, but includes the stuff from the earlier version(s).