I spent a majority of my life during that time doing everything I could to update it on a regular basis and burnt out. Sometimes you just have to let it go.
(I have a Tempest, and I'm decent software dev. Wouldn't mind helping maintain a project around it)
I treat the Tempest as a standalone instrument that happens to output MIDI clock. Nothing's gotten in the way of it being my favorite instrument (at least, once free-running LFOs were added - absolute game changer for claps and snares), and if I had a magic wand, the only thing I'd change is to make the 'noise' samples have a random start offset on the waveform playback (something I used to do with Impulse Tracker), which I think would eliminate the phasing that sometimes happens when two voices use the same noise sample. Maybe next time...