I guess I was misunderstanding … Android uses space and headroom differently from Linux. system can run at 100% full … so, as I understand, it will be userdata which is the blocker. I think I might have been surprised once when a user reported uninstalling an app to clear some headroom. Maybe worth a variation on [HOWTO] Uninstall default Apps. The post details removal of a system app. Here one is attempting to remove the app for user 0 so potentially removal of Browser might take out a significant chunk of the user’s data. Untested and not a thing I have seen recommended before … might help if one thought only a small volume of “extra” space is required. (??)
Alternatively target a user installed app which is potentially a big space user.