OK, let's go a bit deeper into this....I am truly sorry about this Marty...
Nylon and wool are pH sensitive, and you have a chance of causing color loss on both of them with high pH preconditioners. The "three polys", not so much.
As Ron rightly brings up, you cannot tell the total alkalinity of a solution by its pH reading, so you won't know if it has been neutralized unless you test the pH after you have extracted the carpet.
I just talked to a cleaner today who has been prespraying with a 11 + prespray and has had to clear water rinse because of a failed injection system. He now has complaints that carpet is drying with a harsh hand. He had previously used an acid rinse before the failure of his system. So the "feel" of the carpet is also an issue if you don't have an appropriate rinse agent.
Regarding the warranty question:
No one will ever recommend that your cleaning agents exceed a manufacturer's requirement during warranty periods.
Its helpful to understand, though that stain resistant treatments are not very durable, are removed somewhat by traffic and soil, and that even supposed "stain resistant safe" products that say so because the pH is less than 10 often still remove stain resistance because of their total alkalinity and/or solvent additives in their formulation.
If you have little to do during the slow season, get a sample of nylon carpet (good luck with that...carpet stores are having a torrid love affair with "the polys" right now).
In any event, clean a section of the sample with a "just under 10" ph product that should be safe for stain resistance, let it dry, then spill a drink with red dye in it on the sample.
You'll learn a lot from the test.