Yes. I am it's author. Thank you for your interest

=== Some introduction about this.

Proton(https://wiki.mozilla.org/Firefox/Proton)Firefox’s new design released June.01 Photon is 88 or lower design.

Proton’s overall feel is good, but there were a few things I didn’t like and wanted to improve.

- Padding gaps are wide

- Remove icons from panel

- A tab that looks like a button

- Tab indicators (Ex. Only one of the favicon and sound icon is displayed)

I've improved all of these things.

- Padding & Icon: https://github.com/black7375/Firefox-UI-Fix#padding-comparis...

- Tab Indicators: https://github.com/black7375/Firefox-UI-Fix/wiki/Screenshots...

I've also provided a version for those who like Photon.

- https://github.com/black7375/Firefox-UI-Fix/tree/photon-styl...

Experimental legacy edge like hover effect feature: https://user-images.githubusercontent.com/25581533/118779970...

- https://github.com/black7375/Firefox-UI-Fix/tree/interactive...