I’m not sure if you read my answer all the way through: everything you have said here has been accurately answered unless the machine translation has misinterpreted my answer
Do as I did if you don’t believe me: download and try the demo version of MiJoy Pro but contrary to what you say you won’t be able to buy it and KVR Audio doesn’t sell it: they simply say “No longer available”.
As for Reaper I repeat that you will be able to use a joystick as remote control but in no case to send midi data.
I took time to make all this for myself but also for you 