Some months ago, there was another discussion about the Go keys, and MIDI. Maybe you should look for that.
Update. Found this: https://www.midi.org/forum/1195-help-with-missing-midi-implementation-on-new-roland-go-keys-61k
The OP there had various discussions with Roland in an effort to get details about the Go Keys MIDI implementation, and was not getting very far. I don't know if he ever found anything, or rather, if Roland ever got this properly documented.
Having a hardware connection is one thing, and it appears that a MIDI connection IS possible. This is not a lot of use though if you don't know what midi commands are available/supported, how to select voices, how to do any SYSEX, etc. This being 'very vague' is not a lot of help!