Margin from template parts is not visible on select in the Site Editor

[kjellr]

When the contents of a template part include margin, that margin is visible when you edit the template. Notice the whitespace shown to indicate the bottom margin here in Twenty Twenty-Two:

When you're using the Site Editor though, it's unclear that the margin above is actually part of the template part. When I select the template part, the blue outline excludes the margin:

This is a discoverability problem for users. If they'd like to edit that margin, it's hard for them to tell where it's coming from when using the Site Editor.

cc @jameskoster, I'm curious if you have thoughts here.

[jameskoster]

Yeah this feels like a bug to me too. That margin should be visible when editing the template.

The rise of user-defined block paddings and margins also raises the value of something like #36437 as an aid to the discoverability issues you highlighted.

As a side-note, we touched on a similar problem earlier today in #36827 (starting around here). You may be interested in the conversation there.

[kjellr]

Cool, thanks. We're having some parallel discussion here about whether we should be using Margin for this specific Twenty Twenty-Two use case anyway: #37105