Well, as I said I don't know a lot about the whole theory and practice, but when I bought a little dress/car seat/handle carrier for Lucy, the inventor of the product explained how it was modeled after the t-touch theory, tightly wrapping the dog at certain pressure points which is why they seem to stay calm when you pick them up by the handle. It was weird how none of the small dogs seemed as nervous or scared when being held even dangling in the air while wearing these harnesses..
Here is a link to show the t-touch wrapping. I just googled "t touch wrap" and this along with many other sites showed up - What is TTouch?
Like I said, I know next to nothing about it, I think it would probably be best to work with a trainer and train wanted behaviors or tasks during a high anxiety moment, but it seems like a simple enough thing to do as a fail safe while training?
I saw redirected aggression at the dog park, but it was towards the owner not another dog. The owner was trying to pull their dog off another dog it was humping and it started flailing around by the collar, it looked just simply excited, but then it turn around and started biting into the woman's jacket and leg.
I have used thundershirts with some success for Peeves (and to a lesser extent Lily, who is generally not so sensitive) with fear and anxious behavior during fireworks and thunderstorms. I also agree that positive reinforcement of desirable behaviors during counter-conditioning training sessions where you control the triggers (noises) for the outbursts of aggressive behavior is the most likely way to get a long term solution that lets both dogs live peacefully under one roof. It will take a long time, but eventually you should be able to get Stella to give you a conditioned response that you desire in response to the cues that currently stress her out.
Be careful and patient. I hope you get a good outcome.
Lily AKC: CGC CD HIT CDX, RN RA RE RAE RAE2 RAE3 RAE4 RAE5 RAE6 RAE7 Multiple Rally High Combined, NA NAJ; APDT: RL-1; CPE: CL1-R, CL1-H, CL1-F, CL1-S, CL1
Peeves AKC: CGC BN RN RA
Javelin AKC: RN (landed on Long Island July 10, 2015!)