Can I fresh-install and run El Capitan on an Mac mini (3.2GHz 6‑core 8th‑generation Intel Core i7 (Turbo Boost up to 4.6GHz)?

@QuickPost - I find myself with a followup question. Is it possible to use the APFS Volume instructions at https://support.apple.com/en-us/HT208891 to configure a dual volume drive which can boot between Mojave and Catalina?

Let's say my target was the Late 2018 mini which shipped with Mojave initially. Guessing based on what you said, I feel as if I found a mini with Mojave originally installed, I could do this to add Catalina (moving 'forwards' in time)... But that perhaps if it was a newer build with Catalina installed, I would *not* be able to as easily add Mojave (moving 'backwards')? Since it's prior to what shipped, even though the hardware originally was specced for Mojave?

Do you have any idea if this is correct? Or might I still be able to install Mojave in an APFS Volume next to Catalina if it arrived with Catalina to begin with?

Thanks again for any help!

That helps a lot for my sleuth-work to find a unit that can do it! And of course - T2 for increased security as a gatekeeper on that kind of time-warp situation makes perfect sense.

Thanks for such a clear answer!

As an addendum for anyone seeking guidance on reference/legacy builds and finding this thread in years to come, I was able to find a page which summarized the shipping (and thus earliest installable) macOS for Mac hardware lines from 2006 to 2020.

https://mrmacintosh.com/category/10-11-el-capitan/

http://web.archive.org/web/20200513075555/https://mrmacintosh.com/category/10-11-el-capitan/