You could search the add-ons site for helpful reader extensions. That below is one I know of.

https://addons.mozilla.org/firefox/addon/tranquility-1/

That is not possible, reading mode opens an about:reader?url= page and extensions do not work on about pages. If you want to style such a page then you will have to use userContent.css instead, otherwise you are out of luck.

You could search the add-ons site for helpful reader extensions. That below is one I know of. https://addons.mozilla.org/firefox/addon/tranquility-1/

This one did not help. I was still unable to use my accessibility extension with it. I also can't find any reading mode replacements that integrate the features I need.

What accessibility features do you need ?

What accessibility features do you need ?

Bionic reading. It makes the first few letters of a word bold, and makes the rest slightly lighter.

A beautiful popup shows Reader Mode toggle feature and other additional zoom features. If reader mode is not available a pop-up will be shown. If reader mode is available the site will be changed to reader mode. Press the reader mode button again to toggle back to normal mode.

Hope this helps.

A beautiful popup shows Reader Mode toggle feature and other additional zoom features. If reader mode is not available a pop-up will be shown. If reader mode is available the site will be changed to reader mode. Press the reader mode button again to toggle back to normal mode. Hope this helps.

No, this does not help. I don't need zooming or increased text size, what I need is to enable bionic reading, which reader mode does not support.