I took the initiative on expending the scope of this PR to also include Mac support as it seems it needs the same changes.

This was tested with S4 Mk3 screens

You need also to enabled BULK support in our Windows build setups:

Just a heads up here - there seems to be reports of issues on Zulip about Mac and that feature. Let's hold on merging till we have further details and potentially fix the usecase first.

I did some testing on MacOS M1 (Sonoma I believe) and it worked but there might be edge case other arch/OS version

I wonder what the kernel driver is, that needs to be detached, a generic one, that comes with the OS like WinUSB, or a Native Instruments driver for the S4 Mk3.
Maybe the detach of a Kernel driver is not necessary in case of Linux, just because this OS is not supported by Native Instruments?

Maybe the detach of a Kernel driver is not necessary in case of Linux, just because this OS is not supported by Native Instruments?

Yes, I think your theory is correct.
Do you think this means we should potentially rework the Linux part to make it compatible with the fact that NI may (very unlikely) release NI kernel drivers too (and so require a similar libusb opening procedure?

I'm not sure, but it would be good to test this without the NI driver package as well, to get a better understanding.
If the NI drivers are installed, we also need stop the service "NIHardwareService" on Windows, because it otherwise communicates via HID in parallel to Mixxx.

It's worth to mention I had to change the kernel driver from the NI to WinUSB one, so I guess this usecase isn't possible, or is it? I'm not sure how we could allow both kernels (And services) to be toggled on demand, and since I don't have much experience on Windows (nor the setup, and the interest to be honest), it's hard for me to work on a robust comprehensive solution here.

Could we consider merging this as-is as it is improving the overall bulk support on non-Linux platform (especially Mac, allowing bulk to work out of the box on MacOS 14).
Happy to create issues for the installer/further work to do on the Windows side to get that also working out of the box. In the meantime, I'd be happy to create a manual section to help installing WinUSB using some utility like Zadig

Thank you, for addressing this long pending limitation!