This no longer seems to be a problem with Slack 4.0.0, recently released and available via Snap. I modified the gist to only set an icon, which it is still missing, and updated it to work with the new window manager class and icon path.
This no longer seems to be a problem with Slack 4.0.0, recently released and available via Snap. I modified the gist to only set an icon, which it is still missing, and updated it to work with the new window manager class and icon path.