That's correct. Being impatient and topping it up too soon doesn't help the A-Bacs (ammonia oxidizing bacteria) since they only need small amounts of ammonia at this point but it does dump even more overall nitrogen into the system, which will just fuel a bigger nitite spike later on, which just slows down the N-Bacs or leads you to need a few more "kickstart" water changes during the fishless cycle.
Now, when I say to be patient and let it drop all the way down to zero, I'm hoping that it will go down and just reach a clear zero ppm for you in a quick manner. There -are- some cases where beginners seem to get very, very picky about seeing very mild shades of the ammonia indicator reagents and their logs show that they sit there very near zero and quibble over this. In those cases, the test should just have been read as zero and the tank re-dosed with its 3,4,5ppm of ammonia. Things don't need to be that subtle during the early stages of a fishless cycle.
~~waterdrop~~