... Switch is a 2017 device with a graphics core from 2014 with games already optimized to run fine even in the portable mode on a screen less than HalfHD.
Yeah but on the emulator it's negligible when I already get 4k 120 FPS+ as I mentioned. You might get a slight boost if you have a low spec machine but I just tested this on an older AMD laptop and the difference is a few FPS between portable and docked modes in either emulator.
Interested to know what your specs are for 4K 120FPS. That seems like it would require a very high end GPU, pricey kit these days! I'm getting sub 30fps with a 2060, which is still a decent mid range card.
You can already put Yuzu into portable mode, I think what they meant was literally playing portability which you can only do if you have a Steam Deck or similar handheld PC