Yes, it does support name abbreviations, however: You should be careful using them. If there are multiple users for a given pattern (for example, you got "wtfman" and "idunnowtf" and enter "!kick wtf tk") it will not show a list of the ambiguosity but instead kick the first player it finds. So you should try to be disambiguous when using abbreviations within b3. The first it finds is afaik the one with the lower id as it loops over the playerlist.
A tip: Use "!find wtf" then it gives you the ids of the players it finds with that pattern. You can then use the id in console with "/follow x" where x is the id, to follow that player directly or use the id for commands such as kick or tempban.
"/playerlist" in console is of course helpful as well at times
But mostly !find would be the quicker way.