First off, thank you for implementing the 1M polygon limit. It's been great and has allowed me to fit many of my puzzles in to a single file for printing.
However, it's still not enough. Many puzzles I'd like to print have just over 1 million polygons, usually 1.2 to 1.5M polygons. This forces me to split the puzzle in two files, which is undesirable since it's confusing for my customers and it kills off the density discount. I usually stack my parts fairly efficiently and splitting them up does not increase the efficiency of my stacking, which is bad for you.
Can you perhaps consider adding some more server capacity? Or, as a different approach, what about having an option that very large models are added to the site without being checked (showing an appropriate disclaimer)? For me, it's a very rare occurrence that models are rejected or fixed during the initial checking. Furthermore, malformed models could still be spotted by the printer operators.