You REALLY don’t want to do this on a normal drive with Mac stuff on it.

There’s a reason it’s not the default. Story is Apple wanted to do this but gave up. Way way too many Mac apps would load their own resources using the wrong case. I thought I heard even some Apple apps though those could certainly be fixed.

So in the end it never happened. I’m not sure if this was during development or maybe when they dropped Classic. But you don’t want to run Mac software off such a disk. You’re likely to get weird issues.