I can’t tell what you are crusading here. Sorry.
Let’s start over with “Early 2008”. That means the computer is 12 years old!
I lost the system HD that had El Capitan 10.11.6. Even as is, it’s so old that SU2020 won’t work.
I damaged nothing in trying, since the HD was lost anyway.
And since I had a backup of data, giving it a try was a valid option.
Catalina worked.
I just can’t get the drivers. Voila.
But, for some reason, I sense you are simply trying to rub my nose in it and not sure why.
First, telling me you think I didn’t install Catalina (more than a little presumptuous) and now telling me I couldn’t via Apple (pointing out the obvious?!)
So, yeah… you’re right to an extent. Apple would not, could not update this old grandpa of a machine, if that’s your whole point. That’s neither relevant to this nor new information to me. I’ve been an Apple user since the early '80s with the Apple II. I wouldn’t screw with anything unless it was “safe” to do so.
But, whatever risk you are campaigning was null when I had lost the system in the first place… A GREAT TIME to try something unconventional. I think you’d possibly agree to these circumstances for trying something new. I’m quite sure that Catalina on my old machine is excellent if I just wasn’t a SketchUp user. So, in that regard, I can’t agree with you fully. Catalina was running and working… just not on the software I wanted it to work with.
And IF it had worked, there could have been a new solution for me to run SU.
So, if you couldn’t trust that I “did” install Catalina, at least try to trust me when I say that “no harm” was done in this experiment.
Furthermore, for your information, I have two systems installed. The option between the two is presented on Mac startup when holding the ALT key. For this reason, I can go to the Catalina system or choose the Yosemite (which I’m using at the moment). Since losing the original El Capitan system HD, it’s Yosemite I need to upgrade back to 10.11.6.
So, don’t fret too much. My gear is protected and my MacPro 2008 is still working just fine.
Thanks for trying to help though.