He can deny remembering on the spot. Or he might not remember details I want to get into. A 30(b)(6) deponent can't do either of those things, because everything they say is attributed to the agency itself, including lack of knowledge.

ETA: Also, he's probably only on the high level decisions. So e.g. it's quite possible that Pekoske never even knew about the underlying intelligence, testing, conferral with outside groups, etc. Especially for a policy that was enacted in 2006, a decade before he was hired. A 30(b)(6) deponent, again, can't get out of any of that. So long as I give them fair warning of what topics I'm going to cover, they are required to know the answers on behalf of the entire agency.

Unless there's something I want from the Administrator personally, there's really not much reason to depose him. Agencies also tend to fight attempts at "pinnacle" depositions like that, on the basis that e.g. it's wasting the person's time when there are other options available that are just as useful to the deposing party and not as burdensome/costly for the agency. Which, to the extent it's true, is actually a fair point.

They are. However, my APA claims were removed from this case, and considered to come under my pending case in the 1st Circuit.

That doesn't mean APA issues are entirely outside of discovery here — e.g. it could easily go to whether the policy is reasonable, whether it was properly informed, whether people have adequate notice, etc. All of those things are predicates to what constitutes a "reasonable accommodation" under the Rehab Act, since if the base policy isn't reasonable then they can't demand a case-by-case accommodation exception to it in the first place. And there are disparate impact issues and so forth.

FWIW, here's TSA's official policy about disposing of liquids and other "voluntarily abandoned" property. Decide for yourself.