OK - for those interested, you can view androidforums.com in desktop mode in Firefox -
(Copied from another thread)
First - here's a resolution test for the Web and the device that doesn't get things accidentally right or misleading -
http://dev.jeffersonscher.com/resolution.html
Next, here's the instructions to change yours from within Firefox (you'll have to click on the solution button to see it) -
https://support.mozilla.org/en-US/questions/981038
"Assuming the device pixel ratio is closer to 3 than to 1, you can try editing a hidden setting to see whether it improves things.
Open a new tab, and type or paste about:config in the address bar and tap the Enter key on the keyboard. You may want to bookmark this page for future tweaking.
In the search box, type css and then tap the Enter key on the keyboard.
When you find layout.css.devPixelsPerPx tap the Modify button and change the value to 1.0 (typically, you just need to delete the - sign). Tap the OK button.
Switch back to the first tab and reload."
Presto - the desktop version of our site appears in Firefox.
View attachment 89746
(low res screen shot due to Tapatalk compression)