Hi,
So, I tried to design a fantasy computer with a fantasy specification, don't know, I just liked 240x136 and it is very close to 16:9, and yes, we need to fit 8x8 tiles. I agree, 256x144 looks like more reasonable choice, but It's too late to change the resolution :) people already made a lot of games for TIC80 and they will break.
I think fantasy consoles designed for tiny games and you have to choose normal game making tool like Unity or Game Maker If your ambitions doesn't fit current limitations
Thanks and sorry for delay with the response :)