Hi There
I am sorry this is not advice.
I just need to be sure I understand your problem correctly. so I will re-phrase it.
You want usernames to be generated in a secuential fasion when you create a user by just adding 1 user at a time.
Do I understand you correctly?
If so? you want a set-able "default" username in User Manager that comes up as you want to create a single new user, AND the new username must "increace" to the next "number" from the previosly created one?
I can not use CLI yet, but I know the UM I use do not even do that when I use "Batch" user add.
I would like to put serial numbers on vouchers