There is a newsletter produced in Australia that comes out a few times
per year called Intopia. I signed up for it around the time Mozilla
came out with Quantum and screen reader users then were advised to
hold off. Here is their take on things as of June 2018.
If, for some reason you can’t upgrade:
• Both Mozilla and Freedom Scientific agree that users of JAWS 17 with
Firefox 57 and higher are likely to get less than satisfactory
• Users of JAWS 18 with Firefox 57-59 should get reasonable results,
but may encounter some issues.
• The Firefox ESR workaround will not apply for much longer – it is
due to switch to Quantum in September.
• NVDA updates are free and easy to implement individually, but some
people may deliberately be using an older version, for example because
their computer uses an older operating system like Windows Vista, XP
or Windows 7 without Service Pack 1. At this stage, it’s unclear how
well the older NVDA might work with Firefox Quantum browsers.
The bottom line, then, is to upgrade your screen reader to the latest
version and Firefox to its latest version, and things should work as
you expect them to.
If we get further significant information on this issue, we’ll be sure
to bring it to your attention.
My Comment: I would need to buy a Windows 10 machine. Too bad I didn't
take the freebie when offered by the Microsoft Disability Desk a
couple years ago.