Form trigger: default values

The idea is:

It’d be nice to be able to present the user with a default value on a form.

My use case:

I have a form with a date, but I want to put the next Sunday as the default value, as in my form this will almost always be the case.

Are you willing to work on this?

I could work on it, but not sure that I’d have time to write tests, docs, release notes, …