Okay, this is really just so it maybe gets picked up by Google. If you have a custom/homegrown PowerShell Module you want to install in macOS, and have them “live” there as it were, you want to copy the module folder with at least the .psd1 and .psm1 files in it to: ~/.local/share/powershell/Modules. Make sure the module folder has the same name as the module. So in the case of my Get-MacInfo module, (yes, I know, the EFIVersion is a bit weird at the moment), you would create a folder named “Get-MacInfo” in ~/.local/share/powershell/Modules, and copy the Get-MacInfo.psd1 and Get-MacInfo.psm1 files into it, then restart any running powershell sessions. At that point, Get-MacInfo would just work:
% pwsh -c "Get-MacInfo HardwareModelID"
HostName: not set
No need to deal with Import-Module et al.