I actually have 8 GB ram.
Which is ample for Catalina given your uses of the computer.
When I went checking to make sure I saw my Flash Drive and got a scare. I usually only use a tiny bit but now it says something different. See?
Flash Storage Or is that just because I divided it up for future OS's? I haven't reconfigured it yet because I don't want to think again about how to do it.
It is just because you divided it up for future OS's, but in my opinion you are right to be concerned about the lack of free overhead in your MACINTOSH HD partition. Your Flash Drive (a.k.a. SSD or NVMe) realistically does not have sufficient capacity for three operating systems. Technically they can all run in the space you have allocated, but there might not be enough free space to install and upgrade. Mojave will have multiple volumes and Catalina will have more than than Mojave. It might work, but it is equally likely to lead to future difficulties.
As I recall, without going back and rereading over 100 posts, Artie and I, both talked about putting Sierra on
an external drive (in fact I was under the impression you already had a Sierra clone on an external drive which would take care of that handily) and if you are going to Catalina then you have no reason for installing Mojave and
vice-versa. I understand your reticence, but you are allowing it to over-complicate things which will inevitably create unnecessary problems. The best plan is to
KEEP IT SIMPLE.
