You are correct.
We lower pH to 7.2 or so with acid, that will also lower TA, but likely not by 10, but something smaller. Aerate. When pH rises to 7.5, lower it again to 7.2, which will also lower TA a bit. It may take several cycles of lowering TA by 10.
Using 30K pool, If your pH is 7.9 to start, that first addition might get TA to drop by 10, but when pH rises to 7.5, the addition of acid to get to 7.2 will only lower TA by 5. The reason we use the cycle from 7.2 to 7.5 or so is because CO2 outgasses the fastest when pH is low.
I just measure in how long it takes to lower it by 10. I don't count the pH cycles, or how long it takes for the pH to rise.
I can lower TA by 10 in 12 hours. May take a few cycles. The 10 in two hours, include pH back to normal levels.