>>your claim was consensus rules AND hash of most recent block are necessary. this is false, hash of most recent block is not necessary for bootstrapping.

A hash of A block from a trusted third party is needed for a node to bootstrap into a PoS network. Regardless of which block that is, the same amount of trust is required. And getting a more recent one reduces the number of blocks the node needs to download.

Anyway, the point is, the difference in bootrapping between PoW and PoS is in PoS, a hash of a block is also needed from a trusted third party. In both cases, a trusted third party is needed, and if the TTP is malicious, they can totally defraud the user.