Is there a letterbox integer alternative (for NWjs f-screen)

I am making a retro-pixel game, but for PC (through NWjs)

Letterbox integer scale works well, yet the game is very poorly presentable since in most cases it has huge bars along the sides of it :/

Is there a way/lifehack to avoid both using letterbox integer and not have point sampling render poorly?

Or at least a way of making letterbox integer look presentable.

Thank you in advance

UPD : tried changing the resolution to square, not much luck.