XP products are largely assembled by robotics. Not surprised they aren't making a new coil for D2 that is smaller probably because of demand vs tooling and programming costs.

They do have the elliptical hf coil housing that I am sure they could stuff a 9" round windings into with minimal adjustments. That would save molding costs etc. That size coil and proportions is a nice happy medium for high trash areas and still have reasonable ground coverage.

Would take a lot of people to get them to consider it.