Take this practice PSAT without extended time, but put your accommodations requests in motion for SAT & ACT. My understanding is that you do not need to use the accommodations (think there is a question on this when you are signing up online - so need to decide several weeks in advance of the test).

As for the scholarships, the really good ones come from certain colleges - many are southern, public universities. The actual National Merit scholarships are typically one time, $2500/max. Any scholarship is good, but there are schools that offer full tuition or even a full ride for NMF. There are also schools offering full tuition for high SAT and/or ACT scores, even if kid is not NMSF/NMF.

I would recommend some prep. Don't do what my 2016 did (though it turned out fine). School pays for PSAT 9th-11th. Zero prep for 9th & 10th grade PSAT and result was same score on both. Took the SAT with no prep spring of 10th, then did about 6 hours total of random prep across the 3 SAT sections for the October 2014 SAT and PSAT (took PSAT a few days after the SAT). 23 point improvement in PSAT and well above our state historical high cutoff. She thinks she just sort of got lucky, though the repeated PSAT/SAT prior to the 11th grade PSAT likely helped. Also her PSAT score was better than her SAT - typically I have seen the opposite.

Also, try the ACT. My 2016 did better on that than the SAT, though she still is retaking the SAT. She did one practice ACT test a week or two prior to the actual test. Having your kid take practice tests of each (under realistic testing conditions, unlike my kid) should give you an idea of which test is better for him.

And I can start another thread, but if anyone can convince my kid that she does not need to retake a 2200 SAT when she has a 34 ACT, let me know. I also thought she might do better on the SAT than ACT, but turned out to be the opposite.