The deskbar is now part of the haiku package… in my case:
/boot/system/packages/haiku-r1~alpha4_pm_hrev46791-1-x86_gcc2.hpkg
In order to patch the deskbar, one would need to unzip the package, patch the file, and re- package the file then place it in the package folder. I don’t think you can do that while booted from the same install, I could be mistaken.
Actually the right “way” would be to create a “own” Deskbar package wich you place in home/packages and then to blacklist the sytem deskbar - with this setup the change should be also available when you install a new nightly on this partition.
For blacklisting look here: https://www.haiku-os.org/tags/hpkg_0
I don’t know if it’s good or dangerous for a user to be able to easily patch the Deskbar but for me it was always one of the marvels of BeOS relative to other OSes. I miss the approachability and I’ve lost one of the little joys.