In a sense these organisations are the polar opposite of LW. LW attempts to maximise rationality, although not always successfully, and cults attempt to create maximum dependence and control.

I hear some ambiguity there on the word "attempt". In the first case you're talking about the stated motives of the founders and high-status members, whereas in the second case you're talking about a behavior that arises from the social relations in a group. A group can become a cult even if its founders and leaders don't try to be a cult; cultishness is a mode of group behavior.

I'd also caution that "the people who make it their area of interest to keep track of currently active cults" may have some difficulties as well — some are missionaries from larger cults (e.g. conservative Protestantism), for instance ....