We are ready to merge /usr in postmarketOS! It is done for new installations with pmbootstrap master automatically now, and it will be done automatically for existing edge installations in one month.
If you know what you are doing and have an existing edge install, you can already do the /usr merge for your edge install and help us find edge cases (pun intended) where it potentially doesn't work as expected:
https://postmarketos.org/edge/2025/07/27/usr-merge-testing/
Thanks to @pabloyoyoista, @craftyguy, @ariadne, @justsoup, @fossdd, @weirdtreething, @Operachi and everyone else who has contributed to making this possible!