Quote from XinhuanThis is actually more difficult that you'd think it is! This is because the autocomplete is done by wow's default UI code, and has nothing to do with Postal. You should just put your alts on the contact list and click the menu to fill in the name, no typing needed!
Sorry for bothering. I just saw/used it in Postman and thinked, that it's not hard-work for implementation it.
TY for answer and TY for good addon!