I would think that is a software / Buster issue, not a hardware issue. You quoted message refers to Buster. You could try Stretch as a test on the Pi Zero if you wanted.
You can get the older releases here.
It’s only the Pi 4 that has to have Buster / Pi OS.
I have two Pan Tilt full setups, those Pi 3A+'s are running the latest Motion Eye OS.
I did test them from Raspbian though with the Pimoroni software. I don’t think it was Buster though? I’m honestly not sure what edition of Raspbian I was running when i did my initial setup and test?
If I have some free time tomorrow I’ll see if I can swap in a Raspbian SD card and run the installer etc. It will be on a 3A+ though, not a Zero. I don’t really feel like taking things all apart, especially when I think its a software installer issue.