Pretty sure it’s not my flash memory, as nothing else is affected. I have zero dodgy/malicious addons, of that I am sure, I really only use Kodi for local playback.
I took it up here - and found a fix in Matrix that appears to help, although it is not conclusive as I am testing on a full Windows PC and not, therefore, equivalent hardware. But I did realise I was originally wrong and seeing hangs on Windows too, albeit shorter ones.
…so I suspect this may already be a solved issue in Kodi Matrix, in summary. I’ll certainly be testing it once CE betas for Matrix appear…