Well to put a bow on this, after connecting the blade again I don’t seem to be having any issues. When the sound went wonky the last time, I think it might have been an issue with low battery or the wiring issue (or a combination of both). Obviously the wire in the hilt is still an issue, but as the clip demonstrates, it really only seems to be a problem if I swing it hard with the chassis exposed, which isn’t a typical thing to do. Eventually I’ll probably get around to fixing it, but it will be a pain having to crack open the glued-down neopixel connector and dealing with all those wires that have to feed through a very narrow tube to the Proffieboard.
In the meantime I have my new blade and a backup tube (which will need to be cut to size), and with the blade connector sitting flat in the PCB holder (unlike the lob-sided one in my pre-built blade), it seems I can tighten it much less now and still maintain connection, so hopefully that will extend the life of the tube.