[Evolution] how do I modify multiple caldav tasks at once

[thoosogo riseup net]

I need to be able to quickly sort my multitudes of tasks. Ideally I
could select all the tasks to be edited, then hit a keyboard shortcut to
sort the selected tasks via some sort of profile I setup beforehand.

I followed the instructions here:
https://major.io/2015/11/27/custom-keyboard-shortcuts-for-evolution-in-gnome/
and review the accels file, but I don't know what any of the individual
commands listed *mean*, nor does that list seem comprehensive. So while
I see an option for

; (gtk_accel_path "<Actions>/tasks/task-mark-complete" "<Primary>k")

and I can tell that means hitting ctrl-k will mark the selected tasks as
"complete", I don't see any options for the things I care about, like:

- setting a due date for one week from today (or whatever)
- changing the caldav list
- filling the selected tasks to a specific category.

A comprehensive list of actions that I can turn into shortcuts would be
very helpful.