The pole arrived today. It feels more solid than I expected given its price. The collars lock securely and do not slip, there is very little if any flex at full extension, and the best part... the hole in the bottom cap is a 3/8" thread, not a 1/4" as they state! Slap it on a stud and you're ready to rock.
As for the larger threading that holds the cap in to the bottom tube, it's 1/2" diameter according to my calipers, so I'm assuming 1/2"-28 although I don't have anything of that size and pitch to check.
The top 3/8" connector is removable, presumably to help run a mic cable through the rod. The threading holding that top cap on appears to be the same as the bottom. The cap with 3/8" male stud is one piece of machined aluminum.
Maiden voyage will be next Thursday. Here's a picture, extended as far as my basement ceiling would allow.