well the reason i posted as i assumed that now auth(pragmatic) and bt account are pretty much one, changing your username in bt would effectively just be changing your in game name. as his main bt account that he has accomplished top level in is the one he would like to be using, he want to change the association it has with his 96 honor auth account to now be associated with his 100 honor auth account so he can aim for 110.
the other bt account( the one with a few kills), is not required and he made that just to keep track of his other auth accounts username.
i wish he just stuck with his 100 in the first place lol...
I don't care how he will do that, if he will do it by changing names (pic below) but he can already do what he want! There is no more association or so-called linking because there's no more accounts to link, only a battletracker account that theorically tracked his stats in the best way possible.
And again, pragmatic and Battletracker account were a different thing once, and they are a different thing even now. If you had a Battletracker account from the very first day you started playing with that account then it's fine, otherwise your honor might be the right one but your stats will be starting from the day you registered on BT and started playing with that account.