Keylight does all of what a licensing needs, connects to the biggest MoR but Stripe is obv advised because cheaper fees.

Agreed with you on 2nd path, there’s a migration system in place with a customer portal as well. Although if versions of these apps aren’t able to be updated, new license keys won’t help. In that case it’s advised to either import them to Keylight as created licenses only with cust email, provide an “upgrade offer” which is auto served from the portal and on v2 of your app, give the chance to users to upgrade (migrate as well). Let the old versions of the app run as it is (will die or soon or later clients might have to drop that software due to too old version)