I've made a couple minor discoveries with researching Shortcuts, ex CVE-2021-30763, Extract Archive Write Vuln, and (probably the only one that has actually a bit of impact) Hide Shortcuts Action Vulnerability.

iOS Devices

Device Storage Original Firmware Current Firmware Jailbroken? Description
iPhone 11 128GB 13.5.1 13.5.1 Yes My main iPhone. Works great, love it.
iPad (6th Generation) 32GB 12.? 13.5 Yes Great as a test device for modern firmwares.
iPad 2 16GB 7.0-7.0.4 8.4.1 Yes My first ever Apple device. Jailbroken on openpwnage.
iPad (4th Generation) 16GB ? 10.3.3 No Test device. Bought second-hand.
iPad Mini 2 32GB ? 12.5.5 No Test device. Bought second-hand.
iPod Touch 1 8GB ? 3.1.3 Yes Bought second-hand. For fun.