Issues

The undo.data file gets very large - do I need it?

You need it if you want the undo capability, the merge capability, or the journal feature shown in the ‘info’ report. But if it gets large, you can certainly truncate it to save space, just be careful to delete lines from the top of the file, up to and including a separator ‘—’. The simplest way is to simply delete the undo.data file. Note that it does not slow down task, because task does not typically read it. Otherwise task only appends to the file.

Note: To merge from a repository, it must contain an undo.data file, so you can delete the old one, and just touch a new one.