You could always have your editor reformat files in gofumpt's way before viewing code or diffs, and reformat with go fmt when committing.

I've never seen anyone with a workflow like this (lots of people have the second part, of course, but not the first one), nor tooling that makes it a really natural thing to do, but wouldn't it work? There are some pain points if you ever want to pair program or if you use multiple tools to collaborate on code.