Full belly pans on sprint karts

Curious if anyone has experience with full belly pans on a sprint kart? Pretty sure they aren’t legal , but curious none the less…

In some orgs, you can have the pan extend so that it runs under seat and back to the rear bumper, as long at it stays within the frame rails. I saw a Yamaha with it at a USPKS or Route 66 event at NCMP a few years back. I wouldn’t think it would be worth the effort, because most sprinters would have to raise their seats a little.
Now, in short wheelbase enduro, I have plenty of experience with it, but that’s a full pan.

If memory serves, the CIK regs say its can run up to the seat rail. And it would seem most rules sets start with the CIK ruleset.