The_IO_Doctor pointed out that there are many changes in the look of the windows on some boxes. Maybe it'd be a good idea to have some "customisation" options: To be able to choose, for example, how the windows will look on the Twelfth Doctor's exterior when you use it.
Give everyone the MrCrayfishers Digital Clock as it slows down/ ticks back when there is lag. This is a good lag indicator for if someone wants to know if the server is lagging or they are.
A room or circuit you need to open in order to fuel the TARDIS before hitting the "refueler". Breaking the circuit will result in time energy being released from the console and damaging the player and reducing other circuit properties by 10%.
protocols, activate a number of specific controls to activate functions or deactivate, such as turn off the tardis, lock coordinates, emergency mode 1 that would return to a coordinate saved along with a voice hologram, command disks among others
sounds when a component breaks or is missing, and when the artron power runs out, sounds for when the waypoint is saved or loaded
Coloured lights potentially for use in interiors, such as is demonstrated by https://minecraft.curseforge.com/projects/colored-lights (This could add some further detail especially to interiors like the coral)
open the door without needing the key, or lock using the key with the shift command + right button
an animation more similar to that of the series, with that effect of appearing and disappearing
select the demat and remat sounds on the monitor
write the coordinates on the console or monitor