There are ways to flatten warped chips. I guess the easiest thing I'll link a forum post on how to do it. There are some steps and it would probably be easier to see pictures as well. Hopefully this helps out!
This is a piece of what was said in the thread.
"For warped Paulson chips, I typically go 15-20 minutes at 120F. (From experience, I strongly recommend you don't go higher than 130F.) I then remove the clamped chips from the oven and place them on the kitchen counter (NOT in the refrigerator!) to allow them to cool SLOWLY to room temperature. I usually wait about an hour for cooling. Gently tightening the screws during the cooling process is often necessary for best results, as the chips contract while they cool, and you want to maintain pressure on the chips to ensure that they cool FLAT. This process has consistently worked amazingly well for me on both hot-stamped and inlaid chips.
For warped ASM chips, don't even put them in the oven. Really. Just clamp them and leave them overnight. ASM chips are like Play-Doh compared to Paulsons. I found that if you use any heat at all on an ASM chips for even 15 minutes, the chips become squashed, and the chip faces suffer minor damage (flattening of cross hatching, etc.). I've had limited success flattening warped ASM chips by clamping overnight. The lightly warped chips and spinners tend to come out pretty good, but some of the really badly warped chips never get flat enough for me. Your mileage may vary.
One thing I'd like to do to make this process a little easier next time is to order some 40 mm diameter ceramic blanks. When you use standard 39 mm blanks, you have to be very careful to get the ceramics and clays aligned perfectly so that you apply pressure evenly over the entire face of the clay chips."
This was the type of clamp they used as well: https://www.amazon.com/Bessey-LHS-10-10-Inch-Handscrew-Clamp/dp/B001AQMDBM