So being a cheapskate I refused to give up on the expensive goggles and tried to mod them. I started with the clear lens and ended up melting them with my heat gun. Making the best of the situation I decided to use the melted clears to test the melting point and structural integrity of the modded lens. With my Duratrax flashpoint thermometer I measured that the lens starts melting at a very rough 180-200 degrees Celsius. Next I fired point blank, full auto at the melted area with .25 at 400fps. Lens EASILY survived with minor divots. With the information I learned I was much more careful and ultimately successful at flattening the dark lens that came with the goggles. Here is how I did it:
I flattened the lens with a clamp right in the middle of the lens. Next I heated the lens slowly with my heat gun while checking temperatures with my thermometer. I would check temperatures in multiple points around the lens as I want as little temperature difference as possible. Once my thermometer showed 120C I became very careful and monitored the temperature more thoroughly. The goal was to get as much of the lens hovering around 125C-130C for about 5 min or so. If the temp went over 135 I would let it cool for 20-30s while keeping a close eye on the thermometer. After 5 or so minutes at max temp I would let it cool completely and go do other things. I would leave it clamped and do 2-5 heating cycles in a day depending on how much free time I had.
After 3 days I flipped it over and clamped the lens at the edges and repeated as above. The only difference is I had to be extra careful with the temp at the bridge of the goggle as that area seemed to heat up really fast and dissipate slowly. After a week I went from goggles that I could fit a finger around my nose to goggles that seal perfectly, even with a very, very loose strap.
This process does take a few days but your actual time devoted to it per day is very minimal. Just leave the lens clamped until you have time to get back to it. Let me know what you think of my write up. If you think its worthwhile I can do a more in depth guide with pictures and post it in the appropriate sub-forum.