create pit vs conjurer's shift / other teleport effects

[Matthew Morris]

Ok, create pit creates "a 10-foot-by-10-foot extradimensional hole"

Since it's extradimensional, does that make the top of a pit a planar boundary for thinks like shift, dimension door etc?

For that matter since it's an extradimesional space, does it shut down portable holes, haversacks, efficent quivers etc.