In my mind the most important thing when testing with the K-1766 is the Speed-Stir.. I don't get near the accuracy when doing it manually.. With the Speed-Stir there is an instant change when the salt level is reached.. You might get a couple of flashes of color change before you get there, but it is very obvious when you get to right spot..
I have not noticed that temperature has made any real difference.
You can always bring a water sample inside to warm up before testing. I find the salt test to be one of the easier tests to do with or without the speed stir device. But of course it makes it go much faster! Yeah, you'll probably see short flashes of yellow or coral, but once it actually changes you won't mistake that for anything else. Brick colored I call it.
Here in the desert - not often. It doesn't change unless you take water out and add fresh. Evaporation obviously does not effect it and that is really all we have. Our pools do not overflow. Unless you have a sand or DE filter you backwash a lot. Which you don't.
I will be honest. I do not have a drop based salinity test. I have an electronic one given to me by a pool builder that got it on promotion from Hayward. Surprisingly accurate. And about $100 if you buy it!
I have only had to add salt when I have drained/exchanged the water in the pool. I think the MA I use makes up for the tiny bit of water lost due to splashout.
I have a TDS meter that has the probes and am happy, but a Ph one was a bear to calibrate so I’m sticking with a liquid test for now. My (New to me) Hayward SWCG panel is displaying 300ppm (yes 300), and I know I can recalibrate so want the most accurate test I can get.