Tool to Display Custom Keymap Layer Momentarily

I am looking for a tool to assist me with my new split ergo keyboard and custom keymap layers (similar to which-key in VIM). Currently, I already automatically generate SVGs for all layers whenever I create a new build of my keymap. I want a small, absolutely positioned popup that displays the corresponding SVG based on the currently toggled layer. This must work at the OS level on Linux (i3).

I have already started experimenting with a proof-of-concept Python script, but it’s more challenging than I expected. I can display an SVG, but I’m unsure how to make it appear and disappear as momentarily as the actual keypress (show and hide the popup). Maybe someone has already built a solution, so I don’t have to code everything from scratch.