"I wonder about the population distribution getting sampled in IQ tests reflecting an entire race sufficiently, and reflecting possible subgroups. "

If you believe the tests have too small samples, check out the statistics that correlate VERY strongly to IQ / intellectual success in general, and that have even the entire population as samples. Things like:

-SAT tests

-PISA tests

-education level

-income

-wealth (correlates better than income)

-crime statistics

Every single one of those tell the exact same story: there are differences between countries and races, and the differences are very similar to those that have been observed in the IQ studies (for example the adoption studies)

"On the topic, if we bring genetics into it, we wouldn't really be using race as something to connect to genetics"

Yes, we would. Even the AI's of computers have catogorized people of the world to races after getting the genomes of people around the world

"Race" is a very real thing. The genetic studies say so, and even about 99% of people themselves know very precisely which "race" they are, or which exact nation they belong to, even before getting a DNA test to find it out.

The genetic studies on intelligence have already found hundreds of genes linked to higher intelligence - and that those genes are found more often in the "races" that have been scoring higher in the IQ tests

So yes, "race" is real, the sample sizes are large enough, and the differences are partly due to real hereditary genetics (and not just due to the environment, poverity etc).

This of course does not mean some people should be given up on from the gate. But it does mean we shouldn't be wasting any resources trying to secure equality of outcomes

The "Kansas City school experiment" showed once and for all, that trying to destroy the IQ gap by throwing money & resources on the "problem" will not solve anything. Hundreds of millions were wasted, and the gap remained:

https://www.latimes.com/archives/la-xpm-1996-03-27-me-51685-story.html

You can't really fill a bucket any more once it's already full.