Update:
Got the car back from the dealer yesterday. Warranty was approved and injector 3 was replaced along with an oil change and coolant topped off and burped. Spark plug was not fouled so it was not replaced although i will pull it and verify myself. i wonder if they noted it was not an OEM plug. . . or if they were able to tell it wasn't an OEM thermostat when they pulled that out. I highly doubt it as it looks similar at first glance.
Also, the strategy did not change so i'll be putting the car back to my preference soon.
Overall this was the 2nd positive experience i've had from warranty work done at this dealership. The job took longer than expected as they had to get approval from the warranty company(which had me sweating for a day) and had to order in injector o-rings.
I asked one of the service writers if fuel dumping through the exhaust could cause the cats to fail or harm them in general. He said it's hard to say but if i didn't run the car for long with the stuck injector he doubts it would be a big deal. He suggested driving the car on the highway and "getting on it" to let the car breathe and heat up the cats to cook off any residual fuel. I gladly obliged on the way home

Feels good to have the car back . . even in stock form for now.