Yes, there is a slight bow in the propane tank cover where the bolt heads of the Andersen brackets are located. It is barely noticeable due to the rounded nose shape of the cover.
It sounds like you may be concerned about stress to the propane cover caused by the bolt heads on the Andersen frame brackets. People tell me that I am overly particular about quality materials and installing things right the first time. If I thought there was any danger of stress cracking I would have cut 2 inch holes for the bolt heads rather than form the propane cover over them. However, as always, you be the judge.
When you get your Bigfoot you will notice that the propane cover is screwed directly to the frame with two self-tapping iron sheet metal screws (see photo). Although, there was no gap between the cover and the frame originally, there was some stress to the cover. If you remove the two screws and allow the fiberglass cover to "relax", a 1/2 to 3/4 inch gap will develop between the fiberglass cover and the frame.
After installation of my Andersen, at the location of the Andersen frame bracket bolt heads, there is a 1.5 inch gap between the fiberglass cover and the frame. And, at the fore and aft areas of the cover where the new stainless steel metal screws are located there is a 5/8 inch gap that I created with nylon spacers to reduce stress. So, rather than the cover being bowed inward originally 1/2 to 3/4 inch from it "relaxed" position, it is now bowed outward 1/8 to 3/4 from its "relaxed" position.
The cover does not feel or look stressed. There is still room for more flex. A local fiberglass boat repairman told me that it's possible that hot summer days may mold the fiberglass cover to its current shape, in the same manner that fiberglass roofs will sometimes warp under the weight
of heavy AC units.
One more suggestion: The original sheet metal screws that Bigfoot installed in 2005 were rusted into the frame and had to be drilled out. I suggest that you replace the screws on your Bigfoot with stainless steel screws to prevent the them from rusting to the frame, and use "Never Seize" to prevent the frame from rusting to the screw.