If it's worth anything, my impression is that the CPU (and probably GPU) performance of chromebooks varies widely between models. It seems to be particularly dramatic when comparing ARM models against Intel and AMD models.
I don't doubt that low-end CPUs could cause dropped frames during video recording.
If I had to offer any advice, it would be to test as many models as you can and then decide which ones to officially support.
Yeah we have had reports from one other user that his Chromebook sometimes has issues recording both webcam and screen at the same time. I definitely intent to test as many devices as possible and put up a more official page about that.
I don't doubt that low-end CPUs could cause dropped frames during video recording.
If I had to offer any advice, it would be to test as many models as you can and then decide which ones to officially support.