1st, every time the TARDIS makes a flight trip, there should be a cool down for taking another. The cool down time varies by how many blocks you travelled, and by dimension. Upon trying to demat or summon your TARDIS, you get a message saying you can't do that until *insert time here* has passed, and should also get a message for when the TARDIS is ready to make another flight. Once you land from flight mode, the cool down time should be equal to the time you were in flight mode.

2nd, the Kerblam man can be used to deliver items to other people from anywhere. As a block, when right clicked, you get a GUI interface with 1, 27 item slots (Basically a chest named "Kerblam Man") and 2, below that would be a bar that asks "Who would you like to Deliver to?" where you need to type the IGN of the receiver. Once you've put the items in and typed the username in, you can click a button that says "Deliver" and you should hear that electricity sound when mining steel, along with the Kerblam Man disappearing. Then, it should reappear right infant of the receiver, and they'll get a tellraw saying "Special Delivery for <username>!" The Kerblam Man should also work like a safe; only the receiver can open it. A new GUI interface should open with the chest of the same items you put in, and below that, a line of text saying to click a button to send the Kerblam Man back to the deliverer once they have taken their delivery.