If you wish to learn about combined chlorine in pools (not drinking water as in the EPA document you cite), the you can read these two posts -
Chloramines and FC/CYA
Chemistry of Chloramines - indoor commercial pool
Your initial post simply stated you had a Taylor test kit and your signature states "Taylor Technologies". There are many test kits and strips that Taylor markets to the pool world, so without a more precise statement, it would be hard for the reader to know exactly which kit you had. Combine that with you asking about an app that was primarily designed as a test strip reader, and I'm sure you can see how confusing your first post is.
As for the recommendations in that app, there is a lot of not-quite-right information there. If you wish to educate yourself on what the industry says versus what the truth is, you can read these threads -
Certified Pool Operator (CPO) training -- What is not taught
Breakpoint Chlorination
Yes, you are correct that Taylor sells test kits and not chemicals, but Taylor is also a major player in the pool chemical industry. DuPont is the maker of Oxone™ (MPS) which is both heavily marketed to pool chemical manufacturers like ProTeam as well as supported by Taylor through it's MPS interference removal test reagents. Historically speaking, DuPont was a major driving force in pushing MPS as a pool sanitizer and oxidizer (for obvious profit motive reasons) so it is not entirely shocking that an industry leader in pool testing would create a limit for a combined chlorine waste that would necessitate the use of a non-chlorine based shock. However, if you read the articles I suggested at the top of this post, you will see that 0.3ppm CC is nothing to worry about and that chlorine along with UV in sunlight is more than effective enough to destroy CCs without having to resort to using an expensive chemical like MPS. Given the transient nature of CC production in a low bather load residential pool, you will waste more time and money trying to measure and treat CCs than to simply focus on proper FC levels and simply track CCs as an indicator. Even on a fresh fill with treated municipal water that contains CCs (my fill water has 1ppm monochloramine in it for long-term secondary disinfection from our municipal supplier), the CC's will be rapidly destroyed within a day or two after proper FC levels are obtained.
Thanks. I will read all this when I get back. Gotta run for today. Appreciate the links. :thumbup: