With your 35,000 gallon pool and also adding in the 120 ppm CYA that I forgot about (since that also buffers pH), the 28 ounces of Muriatic Acid would have your pH drop to 7.66 and your TA drop to 157 so you might not have noticed this.

Also, as for testing pH with high chlorine, you can add one or two drops of Sodium Thiosulfate (chlorine neutralizer) which is the same reagent you use in your TA test and mix before you add the pH Indicator Solution. Unfortunately, the Sodium Thiosulfate will raise the pH and give you a falsely higher reading, but only by about 0.1 or 0.2 pH so at least you can get rid of the high chlorine to make sure that you aren't really falsely reading a high pH. My guess is that you are reading correctly since your high TA will pretty much force your pH up, but I'm just giving you another alternative to make sure. In general, you don't use Sodium Thiosulfate with the pH test.

I'll check your other post on CYA tablets and respond to that separately.

Richard