D -w as for making that change permanent. I don't think you should, but if you insist, here's how you make some options permanent:

(dolist (v '((magit-pull "--rebase")
             (magit-show-refs "--sort=-committerdate")
             (magit-fetch "--prune")))
    (add-to-list 'transient-values v))

in your case, I think you can try (add-to-list 'transient-values '(magit-diff "--ignore-all-space"))

thanks ag. This is definitely a compromise solution, but it helps a ton to at least have it on the board even if i end up not using it. How on earth did you figure out how to do that?

i just realized i can refresh the buffer and all the status diffs will now ignore whitespace, which is good enough.

i'm not sure why it's not the default to not auto refresh after you choose an option like ignore whitespace.

> How on earth did you figure out how to do that? I don't remember, I think I got frustrated with how https://magit.vc/manual/transient/Saving-Values.html worked (I think I needed it to persist between configs). Had to check how it works.

If you look at my first snippet, one of the things it does, it forces branches to be always sorted. Otherwise, you'd have to use the universal argument whenever you call magit-show-refs and set the option manually.

There are some interesting Diff rendering options in the Magit Status buffer, under the D menu

Sometimes command details are sent to the *messages* buffer when pressing keys. Or consider using a package like command-log or keycast which shows the commands being run when pressing keys

Or try M-x describe-key and press the key to find out what command its running