I have no clear answer about your problems. One thing I must say when you are getting out of the mainstream operating systems and going to the UNIX world when you try to get help the first rule is:
RTFM because they assume that you try to understand and exhaust the possibilities.
In the IRC most likely are some neck-beards old school guys that was thought the RTFM since day 1 because they doesn't have google to "help solve their answers" and they wanna to help since you try and not simply wanna have your "problem solved" because you are lazy. If the guy was rude maybe he had a bad day or it's his way and you have to had patience.
I personally don't like many of the automated tools to prepare USB disks like balenaEtcher because give me mixed results and I sometimes didn't try dd but it's consistent in the results. I tested the following dd command in Tiger and Leopard either in my DSLD PowerBook or my iMac G5 flawlessly
sudo dd bs=4m if=/path/to/ISO/Void\ Linux/void-live-ppc-musl-20200411-xfce.iso of=/dev/diskUSB
If you try on any linux you and follow the manual (
https://docs.voidlinux-ppc.org/installation/live-images/prep.html). About booting from yaboot the manual also cover it but I didn't try since grub in my machines worked well enought.
My Mac's that I described above have 2gb of RAM and I tried the Network (base install) install and the Local (copying from the ISO XFCE in my case) but I don't try to boot from RAM because this machines don't have that much (and the
base system requirements say's that 64m work), but when I return monday I will try to remove 1gb of my PowerBook to see if I would have any problems installing Void.
I didn't have that much time of patience to build a system from scratch like Gentoo or T2SDE (that have PPC variants, but I maybe will try T2SDE for my PS3 later this year) or rootfs tarballs (I don't have experience with this method, so I can't help you with that) but I assume that your iBook should work (and I wanna get a 12" for my collection).
Good readind and good luck, if we can help you just write it. =)