Yes, I have a custom (new) kirby micropub implementation: https://github.com/srijan/kirby-micropub
It works from other micropub clients like quill or micropublish (this reply and last reply were also from a micropub client).

On Zen browser (firefox-based), clicking the extension just gets stuck on "Loading...", and if I go to Manage Extentions -> Preferences and try to add an account, it says "Permission denied for https://srijan.ch/*"

On Chrome, it goes to the indieauth login flow, but after login, it says "Failed to fetch".

Not sure where I can see more logs. Hope this helps.

Similar to my "fork patch system": https://github.com/srijan/superset/blob/main/docs/patches/PATCH_00-PATCHING-SYSTEM.md

Where a doc is maintained per patch to document the intent of each patch, and those changes can be rebased or (worst-case) re-implemented if upstream changes significantly.

Didn't work for me on Firefox - not able to add an account. Permissions issue?

Noticed that the comment form was not working here since my last upgrade of Kirby and the komments plugin. Fixed it now.

I often read on my feed reader by default, but open the original page if I like the article or want to read more from the same author. And yes, often the designs are unique and inspiring.