My latest warranty replacement unit inevitably started with the yaw jitters this week, barely a month after receiving it (the serial number of this one was notably different to previous units, so I'd hoped it might be from a different manufacturing run that didn't have the same quality issues - no such luck...)
This time, instead of asking for yet another replacement I followed others' advice on this thread and tried to fix it myself.
I unscrewed the handle and freed the rotary pot at the top of the stick, blew into it to get rid of any matter that might have got in, and gave it a squirt of WD40. Gave the wires leading up through the stick to the pot a very gentle tug to give them a mm or two of extra slack, and put everything back together.
The yaw issue was no longer there, and after several hours' determined use there's not the slightest hint of it returning.