Hi!
As RainWarrior mentionned, FamiStudio does come with its own sound engine now (which is a derivative of FamiTone2, but with a LOT of features added). Most of them toggable to save RAM/ROM.
A new version was released 2 days ago actually.
Documentation of the sound engine:
https://famistudio.org/doc/soundengine/
Thread announcing the sound engine:
viewtopic.php?f=2&t=20825
If you have question, need help debugging, jump on discord:
https://discord.gg/88UPmxh
Also, FamiStudio can natively open FTM file (official 0.4.6 only, no j0cc, etc.) so if you already composed your song that should get you up and running quickly.
-Mat