I'm surprised I didn't thin of this earlier. Knowing how large this forum is someone is going to have thought of this though. 

HADS - more specifically the Hostile Action Displacement System, is a function a TARDIS has which, when danger is near, allows the TARDIS to automatically travel to a nearby safe location. In the Mod this could be triggered in many ways:

A) When something tries to destroy the TARDIS e.g TNT or being mined

B) When Shot with an Arrow (the Arrow would come too)

C) When touched by water or lava

D) When click on by it's Owner with a sonic screwdriver

E) When there are no blocks beneath it

F) When the TARDIS is stuck in blocks

This would be a cool feature to add for those of use who like seeing TARDIS animations and for roleplay. This would also make sure people don't materialise in unsafe locations e.g You wouldn't suffocate in blocks or fall in lava upon exiting. Also this system would mean you won't end up like the Seventh Doctor and get shot by some nasties upon exiting. But for those who want to regenerate in Eight, it could be toggled in the Monitor (it would be off by default anyway, so you have to remember to set it).