WRT to the NYC exams... I am old enough to remember the SAT and CB folks claiming that their exams were ungamable... this would have been in the late 80's/ early 90's before the infamous renorming.

My view of all these standardised tests is colored by this. For me there are only two possibilities. Either your tests are unbiased and meaningful and any prep is worthless... or whatever you are testing is arbitrary and I would be naive not to prep. You can't have it both ways.

Test like Raven's and the paper folding etc subtests of SB-LM are ungamabele... but people seem to prefer more modern culturally biased tests... If you want gifted programs to use these weird hybrid iq/achievement tests like sages or cogat or even some modern verbally biased iq tests then you can't be outraged when people prep for them.

My experience, personally and as a parent is that gifted individuals will generally, absent 2e issues, still test in the top 2% even on these flawed instruments.