Follow-up: I removed the bolt completely and with some minor coaxing of the clamp with a flat blade screwdriver, the bottom portion popped out pretty painlessly.

I haven't really had experience with this type of post yet but I guess one benefit is the infinite adjustments you can make for saddle angle, although there are other styles of micro-adjust posts.

It's hard to tell from the photos above but fwiw the bottom portion actually does have small triangular notches for the saddle rails.