I'm glad you shared the info with us, this is great, and I'd concur, within reason, to your statement about all boosters being the same on Asian import cars, and i'll add that in addition to the studs on the cabin side of the booster being longer for the spacer, the brake master cylinder studs, on the engine bay side of the booster, have to match the csm style brake master cylinder...
...well at least if you intend to use the stock, csm, evo, dsm,3kgt, brake master cylinder and fluid lines
I recently was at a parts yard and was pulling some parts off of an "95 mitsu expo that had a spacer on it's booster, it might be better then the csm unit, it looked almost like a 1g dsm one as far as size.
I know that the Acura rsx type s sounds more sporty then say a Hyundai/Kia offering, but if you look at specs, the boosters are vary close to the same as far as weight, and both are dual diaphragm, now whether or not they produce different results, that I want to see
, I happen to have a mirage thats getting a big brake upgrade at the moment, and I have not swapped the booster, or the brake master in it yet, but I'm vary much tempted to go and get one of these boosters and then compare it to the red rockets setup, If I decide to do this I'll make a video showing the difference back to back, in a controlled manner, and I'm willing to compare both if I can find one in a parts yard locally, and of course I'll share all findings
The red rocket stops really well with the current setup, you put a half inch or so of force into the brake pedal, and the car is stopping like you would in normal driving, if you push the brake pedal, like you would a stock csm, your passengers will hate you ask me how I know
Honestly I think pedal feel, and travel, is what the upgraded booster helped with the most, because I used to have to push a little bit more in to get the colt to stop... [this was pre boster swap with 2 piston gvr4 rotors and calipers stock booster on 1g dsm brake master cylinder]