A couple points:
I ran Gamutvision on my old mac by creating a Wine package (
https://www.winehq.org). You can also use ICCView, a free website (
https://www.iccview.de) besides Apple's own ColorSync. Finally ArgyllCMS has a lot of profile checking features incorporated. see here for some basics:
https://torger.se/anders/photography/argyll-print.html#toc0And Argyll's command listing for "Creating gamut views"
My amateur impressions playing around with different software packages is that they all give different values, because they all implement their features in different (mathematical) ways, so they're not directly comparable. I did find them useful in showing obvious profile flaws, like misread patches, but the final judging should be done by looking at standard reference images from your printer
