So current workaround: use a Windows laptop to install the MCSDK.exe file and then Zip the MCSDK_full folder and put this into the STM32Cube/Repository folder on mac. :white_heavy_check_mark: Works
Here's the MCSDK_v6.3.2-Full.zip attached. This allows you to open up a project that has been generated with the MC Workbench, CubeMX as a STMCubeIDE project and open up the .ioc file on STM32CubeMX and STM32CubeIDE on Mac devices.
Make the project on a Windows using the MC Workbench + CubeMX for all initial settings that you need.
Using the .zip on Mac you're able to open the .ioc in CubeMX without any errors but the (re)generation of code on Mac will fail because of some fixed path ST is using to find the MCSDK template files.
Our approach was to get started by adding and building as much as we could in the MC Board Designer, MC Workbench and CubeMX on the Windows PC, then generate it once. From that point on we're just programming away instead of using the ST tools to configure some peripherals etc. We use the CMake approach and work in VS-Code.