Installing A Preferred Mac OS
This is a question I was researching back in Jan '24. I got two very helpful answers from PRP_53 & BD Aqua. In the interim I have discovered that it was all for naught as I was looking for the oldest of the newer MacOSs that gave me the 3-finger drag capability. I had one "newer" (2014) iMac (Monterrey) that had it on it. So I pursued trying to get that on all my computers specifically for the purpose mentioned. I eventually discovered on a YT video that the 3 Finger Drag is not a choice found in the trackpad Sys Prefs, it was under the Accessibility Prefs, and I already had it available for ALL my Macs!
So I wasted everyone's time because I didn't know what I was doing. For that I'm sorry. But I did learn new stuff about installing OSs of our choice. Thanks.