proxies

I don't know about organised lobbying but there is certainly an awareness of the 'clustering' of proxy votes you described.  I was part of a group organised by Clover Moore MP that tried to evolve some policies that she could take to amend strata law in NSW but the strata law here is so deeply flawed that the issue of proxies couldn't be given any more than a cursory nod within the time we had available.

I hadn't heard about the limit in Queensland and I can't find any references to it so it may just be wishful thinking.  It would certainly be out of character for that state which still favours developers to a ridiculous extent – it's in the law there, for instance, that the developer can demand a proxy in off-the-plan sales to award a contract for building management (which they then sell and the owners have to finance).  Having been instrumental in a successful campaign to make that illegal here, I am no great admirer of strata law north of the border.

The problem with limiting the number of proxies one person holds is that you run the risk of disenfranchising people who can't find a potential proxy holder who hasn't exceeded their limit.  But by not limiting it, you allow clustering through either active campaigning such as you describe or 'passive' blind votes passed on to a chair by virtue of the fact that they haven't screwed up recently.

Personally, I would favour a voting form that goes out with the agenda and asks the non-attendees to tick a box on all the agenda items.  Sure, there will still be abuses but at least you don't have the situation where one person gets free reign over everything. And it will be hard for counter-arguments to get an airing but it's better than buildings being run solely to benefit one resident and his or her investor mates.