I still don't get what kind of encryption you are talking about. What exact problem are you facing at what exact point? I have never used (or even heard of) swiftbackup, I guess this is a huge knowledge gap for this discussion...
(PS.: if you want to adb push/pull from/to any path outside of /sdcard, you need to have the device rooted and allow root access for "shell")
For AdBlock I think AdAway is pretty much as good as it gets for normal users. I'm using it myself (though with ksu instead of magisk but shouldn't make a difference) and never had any serious problems.
My 14 Pro, came with EU rom, and 2 partitions and encrypted as well. Major hassle when you want to backup/restore/update...
1) Encryption: when in twrp I can't make backups/restore. I can't acces folders, etc, bc, the system is encrypted. I don't know why Xiaomi decided on this, but it quite common for the 14 (and perhaps other devices.)
2) SwiftBackup was recommended to me by a forum member here, as I needed to be able to make backups, where is twrp was failing due to encryption issues.
3) adb pull/push work without the shell. So yay, I was able to back up images.
4) Ad blockers: I usually have with this addressed with Magisk, which I could not install, bc, .... yay encryption. For the browser, I switched to Vivaldi, which has in-build data/tracker/ad blockers.
My phone worked fine, until I decided to update, bc, ppl saying I should always update. Now I'm 3 weeks in (with a pause) to fix this s**t.
Main problem, I can't log in to my google and/or xiaomi account. Authenticator, text, mail, otp, none work. So without google account working, phone is pretty much, just a phone, no apps, mail, etc.