I have no knowledge of the depth that would be required to write code enabling new features in an application…but just FYI, in the link you provided, you said the issue for Custom Keybinds in that project’s GitHub project was closed - it’s open, though. Adding new comments is locked for people who are not direct code contributors to the project, presumably because they wanted to avoid having that GitHub issue turn into a general discussion board about the topic of keyboard shortcuts + Discord + Wayland.
I did a github repository of it around the date of my comment above but I never published it because I ended up believing that no one would be interested and that I was the only idiot who wanted this specific feature… So just for you because you seem to really wanting this feature like me, in the next days I’ll publish the repo and comment it back here!