Hello dear Donncha,
I see you are working to improve your wonderful plugin, and wanted to ask for a feature I've mentioned here a few times:
"caching the homepage for a limited time in preload mode"
I have a busy website with many posts, which I can keep for many weeks as they are. But I would like to have the homepage refresh every half an hour. Right now I solve this by simply not caching the homepage (which is a shame).
Another way of doing it might be do add the function to use legacy caching to the homepage, so that it will get cleared (while the supercached posts, through the preload, will not be cleared).
I'd be happy to hear if there is a chance to see this in your new release.