there's a lot of scaremainering with high ph pre sprays, we've used power burst for years, in fact on nearly every job ( except for the obvious no no's ), rinse with fibre & fabric, jobs a good un !
even wool carpets and delicate suites, the fact is we've never had a problem, or at least not one specific to those products, to me thats worth more than following some "safe" code and doing a rubbish job.
We very rarely agitate either, mostly prespray, tea & biscuits, prespray, extract (t/m), easy life

Some years ago, i knocked over some prespray on a very trashed carpet which we were struggling to clean, and produced an almost new patch on the carpet, it made me realize the prespray is the key factor in carpet cleaning, now we put down twice as much, leave a longer dwell time, and then extract with high temp and about 500 psi, pack up and go home.
I always think now that twice as much prespray is better than having to extract twice as much, less water down means drier carpets.
steve