Wicknix modified the source code of Pale Moon and released it a month ago.
Download of the modified Pale Moon source code: pale-moon-31-ppc-fix.tar.bz2
He compiled a 64-bit PowerPC version with this modified Pale Moon source code a month ago.
Download: palemoon-31.2.linux-powerpc64-void64be.tar.bz2
I compiled a 32-bit PowerPC version with Wicknix's source code for MintPPC, Debian Sid, Fienix, and Void yesterday.
Link to the compiling posts in the Arctic Fox thread: Arctic Fox 27.9.12 (Firefox 63.0) a fork of Pale Moon
Download: palemoon-31.2.0.linux-powerpc-gtk2.void.tar.gz

You can also use another version for very new Linux distributions with Libc 2.34 and pthreads support.
Download: palemoon-31.2.0.linux-powerpc-gtk2.tar.gz
Please test Pale Moon.
Thanks,
Christian