Dusty pretty much nailed this one on the head. There are several different way's of going about it. And there is no clear way that is better then the other. It's just something your going to have too play with and learn for your self.Not sure it's so secretive..jut not really a clear-cut conclusion they they're better. Like the sway bars from 4-5 years ago, it was something that surfaced last year and some guys tried. If you're going to experiment, I'd start with softer springs than you normally run and be careful with the sag. It's tough to pinpoint how much work the bumpstop is doing and to what degree you want it to "impact". You can use firm o-rings or nylon stops on the kingpin, graphite/screw method that hinders the upward travel of the upper arm...or whatever you dream up.
The most agreed upon impression was that your car must be pretty close without it and only use the bumpstop for the final tweak.
i would like to explain why we run bump stops in nascar so all will understand. when Nascar started implementing both high and low ride hight rules around 1999 thats when all learned that the tire data could start incorperating downforce for the grip of the tires. they learned that the attitude of the body out waid the mechanical grip...so they invented what was called coil binding a spring. wich meant traveling till all coils bottomed out. wich was done by having soft springs and a ton of rebound in the shocks wich would hold the cars down. so the car when at speed would stay nose down ass up and make a ton of down force more grip than they could get from even having the chassis right put both together and you are gaining maximum grip. now they cant run the same springs to soft and to much change in speed during a tire run so travels changes and kills downforce (COT)so Nascar lets them have bump stops to stop the travel wich is better than coil binding springs where they were one run at 5000$ at a time go Hendrick lol. they would colapse but good for pre tech and good for after tech because tire pressure would raise the front. just a little inside scoup. so back to bump stops wich is a bunch of rubber shims stacked around the shock shaft to hold ride hight as it bottomed out all the way around the track a lot LESS GRIP but down force made more grip than the right spring rate low front high rear = more down force wich over rides chassis grip. we can already run low front high rear and make better grip so you make your own decision hope this helps and save someone some money .this must be a highly secretive topic, Area 51 stuff, there must be intrest in this cause i got well over 100 looks in 12hrs.