Paulo, no apology is necessary. My previous comments on Mexican tomatoes were actually based on somewhat limited knowledge and definitely could have used further explanation than what I had provided.
The renowned Mexican tomatoes I was referring to are actually the fresh
Mexican tomatoes that we have access to in the states. They cost an arm and a leg, but, out of all the areas where tomatoes come from (CA, Israel, Holland, etc.) Mexican tomatoes, are, by far, the best. The only exception would be local NJ tomatoes, and that's a very small season and an entirely different variety of tomato. I've never tasted a canned Mexican tomato. Much like CA canned tomatoes can have issues on the retail level, it sounds like your supermarkets are getting questionable products as well. When I talked about the renowned fresh Mexicans tomatoes, I was holding out hope (possibly false hope) that someone down your way was canning the fantastic fresh tomatoes that wend their way up here.
Can you get anything in the way of canned crushed tomatoes? Those tend to be the most flavorful and best for this style. Also, I know you're in an urban area, but, as you leave Mexico City, are you liable to find any regionally grown tomatoes? Any small scale producers that are canning their own product?
That is good news, though, that you are beginning to see the advantages of non-SMs tomatoes for NY style pizza.
Before I get into discussing the oven setup, I want to cover some small things that I'm noticing.
First, olive oil, even light olive oil, really has very little history in NY style dough. I can just about guarantee you that Joe's doesn't add it to their dough. Oil is very common, but it's a more neutral tasting oil like soybean oil.
Cake yeast should always be dissolved in water before adding the flour. Salt should be added to the flour before combining the flour with the water. Oil, at least up to 3% oil, can be added to the cake yeast/water mixture before adding the flour.
Your dough formulation should not be causing the bits of unmixed flour. My money is on too slow mixing and/or partial mixing. You don't want flour flying out of the mixer, but, at the same time, you want a speed that will incorporate the flour into water relatively quickly so that it doesn't sit and dry into unmixed bits. Add all the flour to the water at one time and use a speed that will mix the dough quickly, but that isn't so fast that it sends the flour flying.
3 hours at room temp for the dough balls prior to baking should be fine, although it depends a bit on your proofing containers and on your room temp. You'll find different opinions on an ideal pre-bake dough temp, but I find it's probably best to shoot for around 65 F.
I'm not really feeling the flour. Maybe it's the photo, but the crumb is looking a bit underdeveloped and translucent- almost like a high oil dough. Next time, take a photo of the dough after kneading and the dough ball just after balling. It's very possible you can work out the textural issues with an improved bake setup. Let's get your target bake time and then see how it looks.
Unless you start adding dead yeast, which I wouldn't recommend, more yeast won't give you more flavor. 3 days fermentation should give you a very flavorful dough. This could be another bake setup thing- as you get a faster bake time, you get a bit more char/a bit more flavor. Other than that, you can get a bit more flavor by tweaking your formula. 2% salt is fully within the NY style. You don't want to go higher than that, but try 2%. Also, Best's dough probably doesn't contain sugar, but I'm sure that Joe's does. Go with 1% sugar.
Okay, on to the oven setup.
First, unless you're doing a lot of pies at once, you should only need 1/2" UQTs. I noticed that you have a lot of empty space on your oven shelf. Size is a big player in great NY style pies, as it dictates cheese/sauce to rim ratio. You might want to track down a tile cutter and create a larger square to bake on. What is the dimension of your shelf?
There's nothing inherently special about UQTs. UQTs only begin to shine around 600. In your oven, by themselves, UQTs aren't going to hit that. The only way you can hit 600 is with the heat trapping ceiling scenario that I linked to earlier.http://www.pizzamaking.com/forum/index.php/topic,21503.msg217026.html#msg217026
The ceiling, by only allowing just enough air for proper combustion of the gas, traps heat in the lower area and, to an extent, stops heat from reaching the thermostat in the upper area and cycling the oven off. I'm attaching a revised diagram below that shows the different temperature zones.
Track down some regular black glazed tiles and arrange them on the shelf above (black side down), filling in almost all the gaps with foil (leave just a single 1/2" gap down the middle for air flow)
The entire crunch thing is from a 7 minute bake. Trim that to 5 minutes with a proper setup, and the crunch will be gone and you'll have just the right about of flop. The setup I'm describing should not only give you the intense bottom heat you were getting from steel, but, it will give you a matching amount of top browning heat as well, for a quick balanced bake.
Overall, these are all very nitpicky tweaks that I'm recommending. You're very close. All the pies you've made to date look great, and, if you could consistently produce any of them, you'd most likely become very rich, but I'd still like to see you doing something world class/better than Best and Joe's, which I definitely feel is within your grasp.