OK. I think I get how it works now. Did you do anything besides copy FS5 to SS5-7? Because I did that already when I sent my last reply and it was much worse. It was triggering the sample even more. But yours seems to be better (by the way I don't use SS8, I forgot to tell you that.) And now that I go back to my original one it seems to be better since i corrected the FS5 issue, but I still get an CC80 value of 0 coming through on snapshot change. Doesn't seem to have a pattern, just on SS change somtimes. Theoretically, this shouldn't matter because that's the dim value, but still a little concerning.
The device I'm controlling is a Boss RC-5 loop station. But I use it to play recorded samples, not as a looper. I've read that it has some weird midi quirks, so maybe that's part of it, but there's no question the Helix is occasionally sending a zero value. But maybe changed some other parameters in your mod, because yours doesn't do it.
Thanks again for all the help.