Am I right that the final commercial version will basically be a one-time-payment subscription that ensures I get the latest versions on a regular basis that include the latest media keys?
Did you ever consider a montly or annual subscription rather?
Thing is, right now the running a media center requires quite a bit of tinkering in Kodi, keep the makemkv plugin up to date etc, then one cannot say if the MAFIA (Music And Film Industry Association) does not torpedo your product by legal means eventually (I assume you somehow extract the keys and incorporate them in MakeMKV, hence circumventing the key secrecy designed by the bluray syndicate, correct me if I'm wrong).
Then, all I want is a plugin to playback Blurays, not even rip them, and have working menu support.
So, I'd be much more interested in a Kodi plugin, officially maintained and updated for a reasonable annual fee, say 10-15 EUR per year than a one-time payment which, by the way, amounts for about the same as a simple standalone bluray player.