No. Though I've only seen one youtube video claiming lower performance on what was clearly a margin of error difference. Sensationalist youtuber with "reacton edits", really bad one. Even Max Tech couldn't find and report such an issue and you know they would gladly do it.
Still, when you're at thermal capacity there is essentially no difference between 10c and 8c. If you're getting a beefier GPU for the idea of some side gaming (a typical sustained load) it's a bad idea and won't net much of a gain beyond your first five minutes of play.
The only exception would be if you're willing to add a thermal pad but tbh I've already opened up and checked, and due to the thinness of the aluminium plate this generation I would advise against even opening this thing once (until the due-date for the battery). Youtubers don't care if they end up warping the bottom by a degree but end-users will.
If you want a beefier GPU because you have a workflow where the GPU isn't taxed 100% of the time, the 10c GPU can start to make more sense.