Your work is pretty impressive and should be into GTCE and not out of the box. (with the new dev it should be doable)
I dont know if you will maintain your code properly but if you want and if GTCE doesnt wants your code (in case you dont want to code anymore) I can merge your code into mine :).

I have no intentions to drop support, but if I do, you're free to fork it and distribute your own version, as per the license.

As for merging with base GTCE, I don't think that's the right way forward, but thanks for your praise.