Bulk edit of imputations

Hello,

I will need at some point to perform a bulk edit of imputations. Specifically, I will need to spread the total work performed evenly across the duration of the project, after it is finished. This will be done for one project (including several activities), for all users that registered work for the project.

What would be the best way to tackle this ?

Thank you.

Using import, I suppose that would be the 'Timesheet' import ?

But then this would only allow me to add entries, not edit/delete existing entries, correct ?

I have a related issue. I would like to bulk add holidays by adding imputations on administrative projects (more specifically, on an activity inside an administrative project). However I don't know what to put in the"refId" column of the Imputation import. It's a varchar(100), so a string, but "Task" or "task" don't work.
What do I need to put there, and where can I find the description of all importation columns for future needs ?

Thank you !