X11 doesn't limit it, but you will want to enable "Force composition pipeline" to prevent screen tearing. nvidia and Wayland work together btw. It's not a match made in heaven but they do work.
It does work, but its just really glitchy and unstable. Idk how many times Ive woke my pc from sleep and my cursor was just a giant square of gibberish pixels. Or the fact that night light still does not work on GNOME + Wayland because the proprietary driver does not support GAMMA_LUT (this issue has been open for years btw)
I love my AwesomeWM setup. Unless someone completely rewrites it, it will never work with Wayland (as far as I have read the gh issues).
I need this PC to "just work" and I have seen a lot of problems with Wayland and Nvidia drivers, top-quality gaming is a secondary on this one so X11 has been the choice.
Though I am aware stuff is getting better, should probably try it anyway
Thank you everyone, was rather sure that variable refresh rates of different monitors were a hard problem for X11.
So, in nvidia-settings I made my 120Hz one the primary and set the refresh rate from auto to the highest for both monitors (120, 60)
The only difference I noticed was that easyeffects window is now completely unreadable, somehow the text and frames bleeds out/blurs and only gets sharp when hovered with mouse but still buggy. Force-compositon-pipeline did not help there.
Will have to diagnose tomorrow.
No, you can force it to run both monitors at the highest refresh rate, but this can cause tearing on the lower refresh rate monitors. From what I remember, you can choose the monitor to sync to in the Nvidia X settings.
Edit: here's the relevant commit that addresses this (I think).
No. I can't remember what the default behaviour is now. But that isn't true anymore. Source: I'm currently on X11 and my 144 Hz works next to my 75 Hz one with nvidia.