Can someone recommend a Task app that isn't #Nextcloud #Tasks but works about the same and syncs via #CalDAV?

Some quick back of the napkin maths tells me that it takes #NextcloudTasks 30M CPU cycles to process a single task. When you're at around 1000, that means multiple seconds to do anything interesting. Insanity. #JavaScript at its peak.

I'd also like it to actually perform the changes that it told me it did. (It does actually sometimes tell me when it fails but offers no means to retry.)