Custom modeline support for Wayland
Feature summary
Currently on X11 using xrandr, it is possible to add and output specific modelines (custom resolutions and/or refresh rates) to specific displays without having to set the video
kernel parameter, which only allows for specifying resolution and refresh rate, and nothing else (which, for example, would be necessary if outputting to an NTSC or PAL CRT TV that only supports very specific modelines).
How would you like it to work
Add some kind of way to add and output custom modelines (both simple [autogenerated using cvt using resolution and refresh rate as parameters] and detailed [manually inputted]) to specific displays. Either a CLI or GUI app would work well here.
Relevant links, screenshots, screencasts etc.
If a reference GUI implementation is needed, this Windows utility is a good one: https://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU
If a reference CLI is needed, xrandr for X11.
Also apparently, Weston has a method for adding custom modelines in a configuration file as described here: https://superuser.com/questions/1137574/manually-add-a-resolution-to-gnome-with-wayland#1168914