Yes, the issue is that you have 354,964 product combinations that are being consolidated into 7 products. That is what is taking all of the time (4 seconds).
Can you update some of them to simple options, or does every option effect the price? In order to speed up that page we will have to stop using so many options that are creating different products. If they all do effect price we may need to use a premier support ticket to talk through other options about how we can restructure your products to work more quickly.