After a hunt around the area and a good char re. tyre makes and patterns, I purchased a set of Shinko 705’s for my CB500X. So far I’ve covered around 3600km on them in a variety of conditions, on tarmac and gravel, and am well satisfied. They’re certainly a big improvement on Honda’s standard fit.
The bike required a slightly narrower fit than standard on the rear tyre, but this has probably been to the good on gravel / offroad.