The ratchet strap thing works well in the boonies also if a tire gets knocked off the rim. Seen it done a couple of times.
Sorry this is an old thread but I’m having the same exact problem, fractured my neck from it, did you ever find out what this wobble was? It still does it.. my bike is all stock 2020 brute 750epsJust recently when I've gotten up to maybe 35mph or so on a pretty smooth road the steering wheel will wobble back and forth. I know the faster you go the less power steering assist you have, but I'm holding tight etc and it seems to wobble. Is this possibly a loose tire?