Low tire pressure --mostly on the on the front end-- is notorious for giving some bikes the tank slappies. Or with some bikes, too great of a pressure difference between front and back will at times do it.
In other words, sometimes a bike likes a difference of 4 pound pressure between front and rear and if you increase that difference by two pound more to 6 pounds, the front end starts slapping.
In the 80's, the original FZ750 was notorious for this situation. Dial the tire pressure in at exactly 32 front and 36 rear after getting your suspension dialed in properly and the handling of the bike was stellar. But if the front tire pressure went off just two pounds, the handlebars would violently shake right out of your hands on quick acceleration and deceleration, on irregular road surfaces.
Also, if the spring rate is adjusted improperly versus the dampening, the same result had been known to happen on some bikes.
Just a dumb blond guy worthless thought...
But it might pay to have different people that have the problem, and others that don't, post both the tire pressures they are running, as well as their adjustment settings on the front end's suspension.
While it is true that there is a good chance that doing so may end up being absolutely no help at all... There is a small chance that we may see a pattern develop that shows certain tire pressure and/or front end adjustments, where the front end shake is more likely to occur...
Oh look... FRENCH FRIES... Woooo whooooo!