I don’t own a pellet grill but always enjoy a good problem-solving challenge so here’s a thought. If you were to cut down an old cookie cooling rack to fit into the hopper above the tapered area and then zip tie a cheap vibrating motor to it like I’ve linked below to it, wouldn’t that work to keep things from clinging together?
Vibrating Motor
I guess you could do the same with a battery powered adult toy to go cordless per se. At the risk of threatening the G rating here on our forum, I will caveat that the batteries will probably not last all night on a low and slow cook (wink, wink). BTW - I’ve strategically left it up to you to come up with a link of your own for one of those....