How are those generated for multiples?
Say if I have a 5x5 region with all the same color how many criticals are created and where?
Once the criteria for generating 1 crit is fulfilled, it will only generate 1 crit no matter how many more patterns you layer on top of it. So if you’re making a 2x3 with BWGS’s purple, and you tack one more on to also have an L-shape inside it, you only get one crit.
As for placement of the crit, I can’t say for sure - it generally picks the normal positions for one of the composite patterns and uses it.
It will be 1 critical tile. I think it will spawn in the middle. If you have a string of connected matches that would produce multiple critical tiles if they weren’t connected, they will still only make one critical tile. I think the critical tile is made in the center of the first match 5 detected in the string. I think the game detects from the top right to the bottom left. This is why the H and C shapes will fail to be recognized as a match 5, although I’m not sure how exactly that works. The situation you describe would be very rare. Forest fire is the only way I can think of where that’s possible.
Generally it picks the center or joint. So that would be the corner of the L or center of the T. Not sure about a 5x5 block as I don’t know what gets priority. One thing to note is that when matching crit tiles, it makes a HUGE difference in the amount of tiles you can connect. So if you can actually get a 5x5 match, try to wait until you have a critical tile already on the board. You don’t get points for generating the tile, you get points for matching it. So you will get a massive amount of damage! Especially if you have a buffed hero, like Hulk on this PvE, on a favorable map, say the Desert map! 
Has any figured out how the damage is figured on 2 crit tiles in a 3-match?
So, it would look like this: Crit-Color-Crit
I get excited when it lines up and then am always disappointed by the amount of damage. Sometimes I miss the old way crit tiles were multiplied, they used to be so devestating.
Observations based on extensive Magneto use:
- This will sound complicated, but bear with me: When matching a large number of tiles, figure out all of the tiles that will be cleared which are adjacent to tiles that are part of another 3-of-a-kind. Of all of those tiles, the left, topmost tile will be the one replaced with a critical tile (i.e. normal english reading order, left-to-right, top-to-bottom). So in this configuration: X = Matched Tiles, O = other tiles, C = Location that new Critical tile will be created
CXO XXCOO OOXXCXXXOO
XXO OOXXX
XXX
CXO
XXO
XXO
I once figured out whether multiple critical tiles are additive or multiplicative, but I forgot. I will test that tonight and add a post to this topic so you can know.
I haven’t paid close attention, but I always thought the critical tile formed wherever the tile that completed the formation was placed, which usually results in a middle position so:
X
X
C X X
X X C X X
X
C X X
X
X
X C X (This one is kind of special since you can’t actively plan to create this one, it just happens by chance.)
X
The tile (I think) always forms at the spot where you had to move it to form the 5-formation.