I did this ages ago, no response. Also Pam's DeesTroy. But he said that he is working on official TWRP himself now that he got a Poco, so that's probably what he was planning all along.
Anyway, there are still some minor bugs that need to be fixed before it would be accepted. The restore of system/vendor sparse backups is main one.
Finally, OP never actually released device tree for this TWRP. Technically he is breaking XDA rules this whole time. If he can't put it on GitHub and open to all then it will never get accepted anyway.
I was able to restore system and vendor images earlier
Booted on the same clone image before I took the backup
Providing you are on the same android Ver platform or same ROM dev
I needed to make a format data as I went from miui oreo to pie custom ROM so I can decrypt data partition
Then resorted after wipe and it was a replicant to what I backed up