Taurus doesn't have a pressure rating, per se - they test to SAAMI pressures. Most manufacturers generally proof test to about 1-1/2 times the SAAMI pressure.
Some proof test every gun... but I think that's becoming a thing of the past. Now, they proof test the first one they build, and assuming they build the rest of them the same, they presume they're okay...... it's called "first article testing".
The purpose of a proof test, though, is to prove that there is an adequate reserve of strength in the gun, and that repeated use at normal pressures will have no adverse effect.
In your case, though, repeated use at higher than normal pressures will, in fairly short order, result in a broken revolver.... out-of-time cylinder, failure to lock, unlocking and rotating under recoil, excessive end shake, and other problems result from prolonged abuse.
All one needs to really know is to not exceed SAAMI specs for the cartridge and to stop and back off a bit as soon as there are signs of excessive pressure or the published max is reached regarding the particular bullet brand, style, and weight along with other listed components. As I alluded to earlier, an individual gun may not even reach the listed maximum before pressure signs are noted, continuing beyond that point even though it is "published" is only reckless and foolhardy. I personally load most of my rounds in the middle of the pack in regards to powder charge weight. The lesser velocity is very conducive to developing proper shooting technique and is much less likely to lead to poor shooting habits or worst of all, a flinch. it is also much easier on the gun and all parts leading to greater longevity of the gun.
Referring back to your other thread, I've used a lot of Blue Dot in 357 and 38 spl loads and other than being fairly dirty, I have not had issues with it. A faster burn rate of powder may get a few more loads from a pound of powder but most people will not realize much of a savings unless they load an awful lot. Unique is a good powder and one I still use frequently but I wouldn't change thinking a different powder alone would solve the problems you were experiencing.