In theory, if I have configured the public node network correctly, old versions of The Qortal Core, will update upon reaching the update-approval block (meaning, the block that the dev team ((with 20% agreement betwixt them)) decided to 'approve' the transaction, thus making it a permanent portion of the chain, and setting a block by which updates will take place upon any node synchronizing as far.
Essentially - IF YOU'RE ON AN OLD VERSION, IT WILL AUTO-UPDATE IF MY NETWORK IS SETUP CORRECTLY.
Running qortal-1.2.2 now on 64-bit WIN7 and CPU usage is still over 50% on old i3 laptop. Because I'm not running anything with administrative privileges, real loop show starts when right clicked on qortal taskbar icon and start Synchronize clock. Don't do this at home...
I think I might setup a few publicly accessible nodes, but they obviously don't allow you to mint...
I think I might setup a service to host private minting VMs for people. That sounds like something that is a good plan...
Also
you can purchase a raspberry pi 4, and we can provide you an image for it with our custom Qortal Kernel, that runs AMAZINGLY. Any ARM device in theory can work, and we plan to build a bunch of custom ARM kernels.