You can directly edit the downloaded code when using modules, you don’t need your go.work flow at all. I often do it while debugging particularly weird bugs or to better understand library code I’m using.
1. Download the code (or update the copy you downloaded last time you had an issue)
2. Redirect `go build` to use the downloaded copy rather than the upstream copy (either by modifying go.mod or go.work)
3. Do the editing
4. Undo #2
Under the old system, you just had to do #3. And sure, it's not that much work, but it's a bit more than I had to do before.