Another tip is that it doesn’t have to be the same phone as far as the backup and restore is concerned. Enrollment of the TestFlight app might be impacted if the phone changes but that’s just my concern because I haven’t tested that part.

Here’s some links related to these ideas which may be relevant to your interests.

https://support.apple.com/en-us/HT208079 iTunes update that allows installing apps

https://www.idownloadblog.com/2015/12/25/how-to-download-old... Charles proxy how to download specific app versions

https://www.reddit.com/r/jailbreak/comments/auabt7/question_... Context for AppAdmin jailbreak tweak which allows for downgrading apps from device via App Store

http://www.i-funbox.com/en/index.html iFunBox lets you backup and install ipa from device via pc or Mac

http://julioverne.github.io/description.html?id=com.juliover... Jailbreak tweak to auto resign apps and install/backup from device

https://support.apple.com/apple-configurator Apple Configurator allows device management and provisioning by your whitelisted macOS devices