The forum template has had a mod applied that is designed to make it more mobile-friendly this afternoon and the site now passes Google's new Mobile Friendly Test.
This is only an interim step. The next version of the SMF software is fully responsive but is currently only in Beta and not ready to be used on live forums.
I'd be interested to how those of you who use phones and tablets to access the forum find the change please.
I must say that I find the little icons that replace the menu when it's viewed on a smaller screen are a bit dinky but overall it's easier to read.