I use the dichlor/bleach method and it covers 99% of what I do. Once in a rare while I will use a non chlorine shock, but most of the time if a shock is required a double or triple dose of bleach will do the trick. I find 6 in one test strips accurate enough.
When a do a chlorine shock I will test the next time before we use the tub to get a feel if it has dropped down where I want to get in. most of the time I dose with dichlor or bleach depending on where the stabilizer is and can tell by just looking at the water it has done its job. I don’t test every day like I did when we first got the tub. Maybe once a week.
Ok, so using a larger dose of bleach will work for the occasional shock, if needed.
I’ve only HAD to superchlorinate once because I opened the cover to cloudy water after I sanitized for 2 people when our daughter randomly joined us. Other than that one time, my water has been crystal clear from roughly 7ppm dosed after usage for a 30 min, 2 person session.
If MPS is known to throw off the Taylor chlorine test, I’d just assume avoid it so I can trust the results.
I use 6in1 strips for testing on days I use the tub, but will break out the Taylor for weekly checks if the strips indicate an issue. The Taylor kit is awesome so would like to take advantage of it specifically for the CC reading.