> i can confirm, that the Pd-0.55-2 images were built on a Mojava VM,
> whereas the Pd-0.56-2 were built on a Monterey VM.
>
> both were using the identical hdiutil create invocation to build the
> DMG, but apparently it does something different on newer macOS.
>
It does seem likely that Apple would have changed the default filesystem for .dmg files created by hdiutil to APFS, but I think it is still possible to specify HFS+ by using the ‘-fs HFS+’ option with ‘hdiutill create’. I have no idea if the latest Mac systems can even mount HFS+ disk images. Removing that capability would be exactly the sort of thing Apple loves to do…
Mike Green