Making things faster is much easier than making things smaller. I'm sure we can win back a 4% slowdown elsewhere since we have so many more levers to pull from.
This could happen with a user asking their editor to show definition, and then not realizing the result was in some other package, changing it, and saving it, but only if the editor's normal atomic replace mode is disabled. So perhaps that sounds farfetched. But if an AI agent wants to patch some package in a venv, I've seen them bypass the editor and use command line tools to make edits often enough to be concerned. Like corrupting the cache for one package version is already not ideal, and this could potentially affect multiple versions now?
I suppose is this happens the right fix is to nuke the cache completely?