It seems you are mixing up things, the 5B chip just contains a variant of the YM2149 chips which was very common in computers back then (together with AY-3-8910). The 5B itself was only used in a few famicom games, and only one using the sound part.
If you're interested in that sound then check out YM2149/AY-3-8910 instead, there are already many ways to write music for these chips. maxYMiser for Atari ST being one example.
This also makes it the least interesting expansion chip and is the reason it was the last one added to famitracker. Many of the existing tools are likely handling that chip better than famitracker.
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