Wel, just saw how to submit a song to gd, it is a quite boring process but you're willing to do it that's up to you:
You just have to contact a gd elder mod on their discord and submit yout song + proof that you made it, then your account will be whitelisted.

Really cool music btw!

Idk how songs are allowed or not in gd but i sure hope it'll soon be!
Edit 2: Well i just saw that only the artist himself can try to put it in the game by sending a gd head mod throught discord the proof that they made a certain music on ng to be whitelisted, thus making it possible to use in the game, if you're willing to take some of your time and do it, i'll gladly use it!