I tried making 3D-printed magnetic keycaps with magnetic covers that you can easily add icons to!
https://www.printables.com/model/1165592-magnet-keycap-and-cover
Mastodon doesn't want to let me upload the video, so check my Bluesky post for a demonstration of attaching the covers;
https://bsky.app/profile/nekoewen.bsky.social/post/3lgo3fqquss2t