This is a REALLY good question.
I have a similar Anker power strip, guessing it's around the same age too (couple years old?) with a 2x2 port configuration that also behaves similarly. Don't have the model number offhand.
I can also confirm that my "Asometech" 260w giant charger box thing seems to behave like a box with four chargers in it: The ports shown in a group renegotiate when things are connected, but the one PD3.1 port appears to be completely unaffected by the lower powered USB-C ports. I didn't have a chance to try the inductive charger. It is, though, also not very portable.
Newer multi-port chargers not only renegotiate every time, but some are extremely slow at it.