8x8 dual sided vault door

Here is one of my biggest redstone projects ever, an 8x8 dual sided vault door. It was designed before 1.15, so you don't have to use honey (or slime if you only use honey), but you also don't have to only use one of the types, as long as all parts of slimeblocks that are connected are made of the same type.

IMPORTANT STUFF:
It is activated with a lever, and if the lever is on, the door is closed.
The last 4 images have some notes in the description that give some insight in a few things that might be annoying during the building process.