I'm sure it has been brought up before somewhere, but what about integrating personal blacklist of sorts?
The idea's nothing too fancy, just a simple client side blacklist. Local, per-installaiton database file, 2 (3?) gproxy commands (!bladd !blrem [!blinfo ?] or similar) to add/remove (check?) entries, possibly an optional limited lenght note for each entry (sort of like ban info).
What for? Simple. In game lobby, whenever blacklisted player enters it, just pop some info on chat. Nothing more, nothing less. Make it a simple reminder someone earned persona non grata status, and leave it to player to decide what to do about it.
There's plenty of ways it could be improved from that point, but we can save that for another time. Most basic functionality does just enough work.
Back in the days I used to play unhealthy lot of LoD. We had a small group of regulars, but not big enough to get a game going just off that - we needed randoms to fill the rest. I used to run wc3banlist to help me filter out as much gameruining trash from my games as I could. The griefers, trolls, quitters, clear maphackers, etc... you get the idea. Yes, I know I should've just reported everything, but they'd just come back on a new account. For my own purpose, it seemed better to let them keep their acount, and just know who to get rid of before game starts. Besides, not every case is bannable, but I'd still keep people with wrong attitude out of my games, for the sake of not spoiling game experience.
Now, while wc3banlist should still be a thing (I honestly have no idea at this point), it's just another program you have to set up and maintain. You already need the game, custom map downloaded, euroloader, gproxy (that one's merged with loader now, at least), warkeys or another similar tool if you want to remap ability hotkeys via customkeys.txt, another hotkey tool to remap item hotkeys... You get the idea.
I feel like even just the most plain basic functionality can be helpul for anyone caring about making their game experience better. I know my banlist did improve my games by a good margin. I belive this should hold for any small playerbase community, where you see the same nicks over and over again.