Does the most recent version of Elementary OS support Wayland? If so, does the most recent version of Elementary OS support 125% fractional scaling for a fully high-definition monitor?
Currently elementary OS does not support Wayland, and neither will the next release. However, the developers are making efforts to prepare elementary OS for a transition to Wayland in the future. They talk about this some in the recent Platform Changes in elementary OS 6 blog post.
I don't have a source for this, but I remember reading about how they don't plan on adding support for fractional scaling for various reasons.
I really like Elementary OS, but I switched to Pop! OS recently due to easier Wayland support (for Waydroid...). The Elementary OS blog does mention that "future" versions will be use Wayland, so I will look into it again in the future.
Also, instead of using Fractional Scaling, there is a perhaps better way, which is to change the virtual screen resolution using xrandr. You can find out more about this by checking the post on the frame.work computer forums written by the Elementary OS developer. This method might be slightly lower performance, but it should be much more compatible with older apps, etc.
This should work on any device, not just the Framework laptop.