Change a helical to a pancake coil for the same equipment

The big surprise that will happen is that your heating rate is going to drop like a ton of bricks.

Helical coils are extremely efficient when they heat metal parts. Pancake coils are able to heat parts, but the heating rates are going to be much slower, so you would either need a lot more time or a lot more power to achieve the same heating rate. If the heating rate is not important, then a folded pancake or a pancake coil that is shaped where the parts that can still run underneath would be a good option. It will all come down to the geometry of the part, what surface is available to transfer the induction energy into the part and just the design of your process.