Some questions about regions

Hi,
I have some questions about regions(A8-Com):

As i can not disable a region manually(pro only :(), under which circumstances does the engine clip them?

Does it save some clipping time when the Engine frustrum-culls a Region, or is this already mostly compensated by ABT?

In other engines it is possible to have a region only visible, when you are inside the region or looking from another specified region through a portal into the region.

Is such a setup possible too?
Let's say i have a room in a manually created Level. This room has only one Door. The region has the size of the room.

Is it possible that the region is only visible when i am in the region or looking through the doorframe?(manually disabling it, is quite handy here, but not possible -.-)

Are you asking if you can imitate the behavior of region_set?

I am asking about the general behaviour of regions in a Non-Pro environment. usually regions can work like i described above, in other engines.

you could do a for loop each frame wich sets invisible all the entities with a different region than where the player is, and keeps visible only the ones within the same region

regarding to painkiller's suggestion using a material event might be faster than a loop.

SO in short:
Regions in A8 Comercial are USELESS, as they do not introduce any automatism?.

What is about the clipping:
Is Region-COntent clipped, when the region is not within the View-Frustrum(So it does not have to walk down the abt to check each leaf), or is the Region ignored for ABT clipping?

Regions in versions below Pro can be used for triggers, spawning positions and the like (that's what I'm doing in Superku, too).

I bet they are still used for the rendering, too, even without Pro. You could probably test this in a level with some thousand entities.