Seems to me there's two different issues going on here. And BTW - we are kind of starting to beat this to death, but I find it strangely interesting...
One issue is the specifics about two visas per year being available legally vs 180 days a year allowed.
The other is whether you should, as a perma-tourist, even worry about the above, which to me is the most important. What I think bajo_cero is suggesting is that your best bet to be a perma-tourist is not to catch the eyes of the authorities and put yourself in a position that you could be denied entry into the country. It really makes the question about the number of days allowed in country vs number of days on a visa a moot point for a perma-tourist.
By going the Uruguay "renewal" route (I know it's actually not a renewal) you are putting yourself in the scope of the government's sniper rifle and the individual reviewing your passport can choose to pull or not pull the trigger on denying you entry. Just like any other country I know, the immigrations officer has the sovereign right, at that moment, to deny you entry because he partied too late last night and he's in a bad mood. Of course, he could catch hell later on if the person attempting to enter files a complaint and his case was reviewed, but that doesn't help in the moment for the traveler.
In reality, the trigger here is not well-oiled and a bit rusty, so the trigger doesn't get pulled very often. Just following the sniper rifle metaphor. I don't mean to imply that immigrations is sloppy, but I think it's more likely the trigger is not well-oiled on purpose; i.e., it's a concious policy, CURRENTLY, to allow the "abuse" to continue.
So the best thing for someone to do who is planning on staying here for a long period of time: don't leave the country if you can help it. Certainly don't do it on the 90 day anniversary of your last entrance into the country because the risk, though low CURRENTLY, isn't worth it.
Now, for someone like shoush, I think you don't worry about it, not to the point of losing sleep, certainly. You do what you have to do.
The likelihood of being denied entry is pretty small. Yes, it is a possibility and I have heard second-hand that it's happened, but those are two people out of maybe a hundred or so people that I personally know or have known over the last six years who have done this with no issues (not all necessarily "perma-tourists", but have been here many times a year, in and out sometimes for months stay at a time, etc).
Also, if I understood right, you've stayed nines month a year out of the last three years, which means 8 or 9 visa trips total (3 times a year for three years). 18 stamps more or less? I bet that's not too bad. Maybe lessens your changes to get nailed.
Hell, if you're really worried about it and want to make absolutely certain, get a civil marriage certificate and do the wedding in a church. I don't know what you're planning, but even if you weren't planning on getting married in a church, a civil wedding isn't great for celebrating - it's what comes afterward at the boda (without a church wedding I mean). At least then you'd have a strong case for getting back in the country, if for absolute bad luck you were denied entry later.
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Nothing in this world is zero-risk.
I think bajo_cero is correct in his suggestions, and particularly that one should not just completely ignore the possibility of being denied entry. Things are changing and as bajo_cero said, Cristina is very nationalistic. Look at the countries she's pissing off, seemingly without regard to consequences. Look at the laws that are being passed related to foreign ownership of land and the other items bajo_cero mentions.
These are not the acts of someone who is exactly welcoming foreigners and a lot of the way things are being handled by immigrations officers could change, from a policy standpoint.
