You hit the nail mostly on the head: 90% of the lowering springs designed for our cars have insufficient spring rate, and they lower the struts to the bottom of their travel. Meaning WAY too low to be truly useful on track or on rough roads.
EDD, H&R, APR, VWR, and others.
Neuspeed Sports have excellent rates but are also (still) SUPER low, compared to the ideal ride height and suspension stroke for a street car.
My H&R OE Sports were divine at first, but eventually settled a good 8-10mm lower than I want. Meaning what was a 2-finger gap is now closer to 1, which is purdy low for a 90% street car. They look slick, but I need more room for compression travel.
I am considering the Neuspeed RS3 springs or the 034 Motorsport offerings for the S3 and RS3. They have a MUCH heavier spring rate without being too punishing on the street. This would effectively be the poor man's solution to the $1200 Bilstein B14s, since I scored a screaming deal on my B8s, and can sell off the H&Rs to cover half the cost of the next springs.
The B8s are a brilliant damper when paired with the correct spring and ride height. They handled all the track abuse I threw at them. They control body motions sufficiently to allow the car to put the power down (even in 1st!), which is huge. Just add better springs.
This is the route I'm considering next year:
034 RS3 springs (non-MR):
https://www.034motorsport.com/dynam...rs3-quattro-performance-lowering-springs.html
034 S3 springs (non-MR):
https://www.034motorsport.com/dynamic-lowering-springs-for-8v-audi-a3-s3-non-magride.html
The last one has the PERFECT ride height for a street and track car that's actually driven hard.
Listed curb weight for the S3 is 3462lbs. My GTI is right at 3100-3150 before I get in it. So those springs on a GTI will sit a bit higher. How much, I can't say. Only one person so far has run these springs and it was on a GSW (wagon) w/4-motion, so the two were much closer in curb weights.
A 3350lb Golf R would be a perfect candidate for the S3 or RS3 springs above, given its heavier curb.
Listing this here not to hijack, but to help others considering the B8s and setting up an optimal suspension for under $1k.
Proper spring selection would negate the original post's need to adjust the internal bumpstops.
Hope this all makes sense in writing for the readers.
-the VW junkie