Aha, the perfect engineering solution - stick with what works!Right after posting the above, system froze on kernel 6.12.
Tried wl driver again and got freeze on 6.12.
Checked to be sure and ibt=off was saved in grub.
Thanks for all the help, but at this point I think I will just stick with kernel 5.15 till support ends, and then get a usb wifi dongle.
I did try to use an alternative driver on my 15,1 iMac but it turns out the wl module is the only one there is for it. The brcmsmac is the right open-source driver for your device, the trick is to get it working. This thread will still be here when your kernel support ends if you want to give it another go.