That’s more or less what I do. I try to feed enough so I get a good amount of runoff, maybe a pint or so, to test. Then in my next feeding, I adjust like you said, but I try not to go under 6.2 going in. If it gets near or over 7 I just flush. How hard is your water? If it’s pretty bad like mine, you might see your pH swing pretty high requiring a flush, but FF has regular flushing in their schedule anyway.
You should invest in a TDS, or total dissolved solids, meter, and check it. This will affect how you should be feeding, mainly cal mag. I doubt you need to add much if you’re using tap water. But, especially with an auto, you don’t want to overfeed and stunt her.