Chatter is a word used to describe several different things. What he described as chatter is correct and accurate. You have not experienced this "flapping" of the noes and tail most likely because I dont think you have ever ridden rocker?
Yeah I should have re-read the OP before posting. I've seen guys riding powder skis with the tip and tail flapping around while they were riding groomers. Sounds like that's what the OP is talking about?
Seemed totally normal although it's one more thing keeping me from riding a rocker board. I did look down a couple times at my "lifted tip" yesterday
and saw that it flaps around a bit on groomers. Only in cruise mode though, once the edge is raised and carving commences it settles right down.