I don't understand how am I supposed to whitelist blocks for carrying...

I added some entries to the config: here's the relevant part of it. However, it doesn't do anything and I can still pick up any block.

Not sure if it's a bug or I am doing something wrong. I tried doing it with a script and it didn't work either, so it might be a bug.

Whitelists and blacklists add to the list; I don't think there's an option to just disable the default heuristics (which are, generally, "all blocks which don't have tile entities, except liquids and some oddball cases") at this time.