Gamescope should solve your issues because the game won't be able to change your desktop resolution. It basically runs the game through xwayland in a wayland compositor , which in turn runs in your xorg/i3 session.

It introduces two or so frames of latency due to forced vsync, but many people don't notice it (or prefer it over tearing).

Another solution might be to enable wine virtual desktop, which might stop the game from changing your actual resolution. It solved some cursor issues in Overwatch a few years ago, but I might be misremembering.