scaling bigger is better, but you can also set the resolution to 320x180, fullscreen quality to high, and it will automatically upscale if possible with the appropriate fullscreen mode
rescaling in engine or in external programs is better?
I also thought about doing the 320x180 project but as I said it would make some animations not smooth.
Sorry if I didn't understand your answer completely but not being a native speaker I don't understand some things directly, anyway thanks for the reply!