In theory, it is cache oblivious, and the CO-DAM model informs our decisions about the implementation, but no, the implementation itself isn't actually cache oblivious. Shh, don't tell on us.

A "fractal tree" is defined by our marketing team as "whatever it is we actually implement." If you want to talk cache-oblivious data structures, we can talk about things like the COLA and cache-oblivious streaming B-trees which have rigorous definitions in the literature. At some point, if you want to achieve a certain level of detail, you have to pick one or the other in order to continue the conversation.