Itunes iOS 12.2 backup password encryption

[Futschel]

Dear Ladies and Gentleman,
I try to encrypt an iOS Backup Password Version 12.2


I created an minifest12.2.txt with the itunes_backup2hashcat.pl from philsmd
i started the progress within CMD : 
 

Code:

hashcat64.exe -d 1 manifest12.2.txt -m 14800 -a 3 ?d?d?d?d --force

This is nicely working, what can I try if the password Characters count and type is not known by the enduser ?
So if he don't know which characters he used and even when the length is not known any more

Kind regards, Futschel