Sorry, I was just trying to illustrate the positive side of this particular platform. I don't think it would have been possible to scale to that size on just 3 engineers without GAE (or a similar PaaS like Heroku). If it means living with a 10m request deadline (which yes I do find occasionally annoying), it has proven a worthwhile tradeoff.
At any rate it sounds like there's no straightforward solution and I'm on my own. I'll figure something out. I appreciate your time.
There are Shopify engineers out there that you can engage, and since they work on exactly your domain here (Delivery Profiles) I am sure they would LOVE to hear about your issue. I have been helped over the years many times by these "angels", in the sense that here in the forums, I get crickets chirping often, as no one can help me. Annoying as hell yes! But c'est la vie.
I was also stumped by Delivery Profiles and was gifted some nice code that explained it much much better than I could've gleaned from the documentation. So as a stop-gap measure sometimes they do reach out.
Often I hit the wall, and realize, there are zero others out there that have a solution for me because there just is not a solution at this time. So I have learned to be somewhat patient. That being said, if years pass, I get frustrated, as I see it as money left on the table.