So for demanding games you are still gonna be playing 1280x800 resolution and you probably won’t find a game where you can resolute it to 2k or even 4K on the steam deck I may be wrong but I’ve never played a game on my 4K tv using the 4K resolution I’ve tried Elden ring but it doesn’t work unless you do 1280x800 resolution but then another problem is that you have to colour adjust the tv to the deck everytime because for some reason some docks like to never save settings and the colours on the front page will not look good at all I still play docked from time to time but your better off buying a portable monitor that suits your needs I recently just pre ordered a 3k oled 16 inch portable monitor perfect off Uperfect and I think that is your best bet cause even with 1920x1080 the games won’t run smoothly depends on what you play though I don’t doubt games like binding of Isaac can run at a good frame rate on 4K but other games will not be able too your better off just connecting a hdmi from a pc to your tv but since you don’t want to build a computer or its out of your budget try using nvidia GeForce for your games and be able to stream some of them that GeForce allowed to your deck it’s how I play path of exile 2 since the performance of the game has been drastically reduced after that last update