I don't think that's accurate—homebrew specifically says that it only uses the .linuxbrew directory when a formula contains a hardcoded path (which it scans for

I don't think that's accurate—homebrew specifically says that it only uses the .linuxbrew directory when a formula contains a hardcoded path (which it scans for), and only if you choose not to install it from source. So, based on the responses from the maintainers, for the .linuxbrew directory to be used, you have to satisfy 2 conditions: 1. you have to be installing one of the ~10% of formula that isn't trivially relocatable. 2. you have to be using a precompiled binary (which it seems like homebrew is smart enough to not do if condition #1 fails and you're not using sudo)