Display modes can be exported from Rhino for Windows and imported into Rhino for Mac. However, there is one step you may not be aware of. Rhino for Windows exports the INI in text format in UTF-16-LE. Programs on the Mac can not read this format.
After exporting the INI from Rhino for Windows, open in Notepad and save it as UTF-8 or ASCI. Then send it to to your Mac computer and import as a display mode. Below are the detailed steps.