Hi Christopher,
The old extension was doing something we don't really recommend now which is modifying q2 styling from an extension. This likely won't work with the future SDK accounts extension with composable dashboard. You can make this work with the currrent dashboard though and we would likely approve this with a uux_payload: https://docs.q2developer.com/docs/guides/frontend_development/uux_payload.html
If your FI plans on moving to Composable Dashboard in the near future you may look into forking that repo and running your own in the future. Or at least part of that extension yourself.
Thank you,
Trey Teter