On the websites I work on I have stopped testing on Firefox for the most part. I do testing once in a while, but I'd rather spend the time to make the site more accessible since it's a larger group than Firefox users.
If you abandon stanards which requires testing with different implementations you absolutely abandon acessibility for vastly more people in the future, imho.
Happy that I use my time to try to help your disability and make your life easier rather than make sure that a web browser that hardly anyone uses work 100% correctly.
Surely, most of the time Firefox will work just fine or at least good enough and by that standard I am sure that a site that has put some focus for it being easier to read with a screen reader is more important?
