@dsgerbc @tm1v2 Currently my rear hub to fender distance is 415mm. I have the Model Y LR and stock distance is around 432mm, so I'm lowered about 17mm. I'm probably currently around the stock height for the MYP, and definitely still have more ground clearance than an OEM Model 3. With the 12k springs I should be able to have enough compression travel to not hit the bump stops in a jarring way without risking the battery.
The recommending spring perch setting of 20mm for Model Y resulted in my rear ride height being higher than stock, that's why I dropped it to 0 just to get some modest ride height drop and match the front.
At the recommended damper length and recommended height of 20mm for the rear spring perch and ride height greater than stock, I was still hitting bump stocks worse than stock. That's how bad the compression travel setup situation is.
I'll talk to them tomorrow. I'm starting to get a sense that the Y and 3 geometry is different enough that this kit works for the 3 but not the Y.