I have actually only ever seen drops when running a combined CPU and GPU load in a game over an extended period of time (2+ hours). I haven’t tested a synthetic combined load yet, although I might do that when I get time just to see if it’s more consistently reproducible for me. The fact that it happens more often for you is interesting.
Out of curiosity, what’s the ambient temperature in the place you use the device? My room does have an unusually high ambient temperature most of the time, close to 80 degrees F/26 degrees C. If this is a thermal issue, that might be an exacerbating factor.