I just got a 2012 MacMini, and it happens to be running Mojave. I'd like to easily boot into multiple OSes and have an SSD I can install into the Mac.
Before I make a huge mistake and waste a lot of time, I'd like to ask if the APFS file system of Mojave is going to be an issue. By this, I mean, can I still partition the SSD into 2-4 drives, and load each as I want? Will an old OS have an issue seeing the Mojave drive or vice versa?
Update - I installed an SSD, and it's running Mojave. I would still like to know if I'd be wasting my time partitioning the SSD to 2 partitions so I can use one with Yosemite and the other, Mojave. The exact question - "Can a partitioned drive have 2 file formats? One, APFS, the other, the 'old' Mac OS extended journaled (HFS?)?