This is the same rationale why I filed https://smartgit.userecho.com/topics/13-quick-way-to-show-the-files-that-are-being-worked-on-in-this-branch/

There should be a way to checkout a branch, then quickly open the files you had been working on in that branch. Either from the log's modified files pane, or from the main window's files pane with "most recently modified" column, etc.

Yes

"What if you deleted a few files in your branch - should they also be shown for editing (or just those available in the working copy)?"

Just those files that currently exist, like it currently shows.

"Do you need to see the changes made in your branch or just the files (that were changed in your branch) in its current working tree state?"

Just the files. In the main Files pane, have a column for "Latest commit" or something that shows the date of the most recent commit that affected that file.

Showing files not yet committed doesn't help: I want to see files that were recently committed.

Log doesn't help because I can't open files from the Log.

A column of "last committed date" would help, because I could sort by that column and the most recently edited files (in this branch) would be listed at the top, and then I can drag the ones I want into an IDE. Switching to another branch that modifies all the files and switching back wouldn't change this column, because it's based on commit history, not on filesystem dates.

Kind of like the right-hand side of Github's display: https://github.com/scipy/scipy/tree/master/scipy

I want to open a branch, immediately see the 3 files (out of thousands) that I was working on in this branch, and open them in an editor.

Currently I have to checkout a branch, go to the log, search through it to see which files I modified, copy their relative path, open IDE, File -> Open, try to find the root folder that the relative path is based on, paste in the rest of the relative path, etc. etc. or manually type in their names to the main file search box and hope that there aren't other files with the same name in other folders (which there often are), etc.