macos 15.4 beta claims to support FSKit. Is there an FSKit sample available? I don't see anything useful in the published docs.

Looking for any more documentation on FSKit - https://developer.apple.com/documentation/fskit?language=objc I don't see any examples or sessions on it, but it looks fascinating. Attempted to try to put something together and immediately ran into failed at lookup with error 159 - Sandbox restriction

Capability to read and write ofd HFS disks on Mac has been removed since a long time. Capability to simply read was also removed since Catalina I think. That is surprising and sometimes frustrating. I still use a 90's MacBook for a few tasks and need from time to time to transfer files to newer Mac or read some old files stored on 3.5" disks. Solution I use is to read the disk on an old Mac with MacOS 10.6 (I'm lucky enough to have kept one) and transfer to USB stick or airdrop… As there is no USB port on the Macbook of course (and I have no more a working 56k modem to transfer by mail), only option if not 3,5" disk is using PCMCIA port on the MacBook for writing to an SD Card to be read in Mac Sonoma. But reading directly 3.5" disk would be great. Hence my questions for the forum: how hard would it be to write such a driver for READING only HFS on Mac Sonoma? There are some software like FuseHFS. Did anyone experience it ? Did anyone have a look at the source code (said to be open source). does anyone know why Apple removed such capability (I thought it was a tiny piece of code compared to the GB of present MacOS)? Thanks for any insights on the matter.

So if one were to start the attempt of porting an existing kext VFS filesystem, to use the new FSKit (Since presumably kexts could go away), how would that look now? Is it ready? Are there any samples out there that already works (Filesystem using FSKit) ? How is the documentation? ChatGPT did not seem to know much at all. What would be Apple's reception to that? How flexible is FSKit ? Is it locked to the idea of a mount is connected to a physical device (or partition)? Or is it more virtual, in that I will have a pool of disks, and present 1, or many, mount points?