I think you can do the same as like electrum since electron cash is made by developers of electrum .

I searched that there are other people too are  having  error when installing electron cash in their mac i just found it here https://www.youtube.com/watch?v=VTylS6em-G0
I searched this one and maybe it can also help you out to install electron cash in your mac here check it. https://github.com/electron/electron/blob/master/docs/tutorial/mac-app-store-submission-guide.md