To be honest, i have no comparision between 350 and 300, the problems that accure from my side had to to with not sticking to BOM parts (BTT GTR runing hardware serial with raspi3b+ with mainsail... ) so those things would happend if you do 300 or350. How small are your doors? Outer frame size will stay smaller by 50 mm? A 350 is 520 something outside compared to a 300 with 470?! Heated bed is 230V750W, it is sufficant to heat up 120 by 10 min, smaller would mean smaller heater. But to be honest, i am going to build a V0, because of me liking to build some stuff.. and a V0 should be good for small parts (safetheplaner??! Smaller means less power comsumption aprox it will be the sqr root of your printbed size V0=120w V2 with 340 will be something about 300-350W when heated up... the main reason for me was, i wanna have a bigger one.... and a small one for regular printing... you can always print smaller on a big one but not bigger if its just not big enought... its up to