So yeah 4B.
Everything I've read on it suggests it is
1) rooted in TERF exclusionary ideology
2) a fringe aspect of Korean feminism that had a brief moment in the spotlight there
3) Before being adopted by western white women who seem to also overlappingly really love Harry Potter. Appropriated by western TERF colonists in other words.
4) "The irony of 4B is that it doesn’t even scissor out the patriarchy because its logic continues to center it...", writes Marcie Bianco.
Cool, cool.