I just noticed that PlayOnMac does NOT run the system version of wine even though in the GUI is says it's running the "System" version.
At the bottom of my error log, I see wine version = 6.0.
But the version I installed via brew (wine-staging) is version 7.13.
So I started hunting to find where this version 6 is install that PlayOnMac is using... and I found it.
PlayOnMac is using the version that's installed in "/Applications/PlayOnMac.app/Contents/Resources/unix/wine/bin" and completely ignoring the system version of wine. Which is the opposite of what the GUI says it's doing.
$ pwd
/Applications/PlayOnMac.app/Contents/Resources/unix/wine/bin
$ ls -alt
total 1624
drwxr-xr-x@ 9 jackal admin 288 Aug 17 2021 .
-rwxr-xr-x@ 1 jackal admin 33920 Aug 17 2021 wine32on64
-rwxr-xr-x@ 1 jackal admin 37472 Aug 17 2021 wine32on64-preloader
-rwxr-xr-x@ 1 jackal admin 33920 Aug 17 2021 wine64
-rwxr-xr-x@ 1 jackal admin 37472 Aug 17 2021 wine64-preloader
-rwxr-xr-x@ 1 jackal admin 598800 Aug 17 2021 wineserver
-rwxr-xr-x@ 1 jackal admin 33792 Aug 17 2021 wine
-rwxr-xr-x@ 1 jackal admin 33216 Aug 17 2021 wine-preloader
drwxr-xr-x@ 7 jackal admin 224 Aug 17 2021 ..
$ ./wine64 --version
wine-6.0
$ wine64 --version
wine-7.13 (Staging)