Thanks for all the feedback.
As I said in my OP, next step is to get actual spring measurements.
But my whole hypothesis is that at a certain level of compression, the stock bump stop will get so stiff that it doesn't matter what kind of aftermarket 'progressive' spring rate you have...
When you use lowering springs that are too aggressive, your handling will become less linear and predictable, and you will get more understeer...
Stay tuned for more in the future.
Below is a video front a fellow member who had too an inappropriate bump stop set up in the rear axle
Get the bumpstop tuning right or this is what happens. Sudden and violent oversteer. I remember this day because I didn't think that bumpstops were the issue. I was on the phone with my shock guy and he had me decreasing the rear compression, which ultimately made it worse. Trimming the bumpstop .5" eventually solved the problem.
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