Camera Alignment

At many points throughout the run, you will lose camera control as the camera pans to a specific direction. This panning is incredibly slow, and time can be saved by manually moving the camera as close as possible to the direction it wants to go to before you lose camera control. There are too many of these moments to list them all with the precise directions you should look.

Setting The Musical Instrument in Spire

Since you don't need to stop on each setting for the corresponding lock to open, a fair bit of time can be saved by playing each cable in a particular order. Remember that 12 is the highest setting and 0 is the lowest setting, so you can reach them very quickly. It's also advisable to count the lights turning on and off to know how many notches each slider has moved. The order of settings is as follows:

Set cable 2 to 12
Set cable 1 to 6
Set cable 3 to 7 (1 notch above cable 1)
Set cable 1 to 3 (down 3 notches)
Set cable 2 to 0, then 5 (this is halfway between cables 1 and 3)
Set cable 3 to 5 (this is level with cable 2)
Set cable 1 to 12
Set cable 3 to 12
Set cable 2 to 12

A faster solution uses the following order:

10 5 5
12 12 12
6 12 4
3 1 7 and the cables should be set as follows:
Set cable 2 to 5
Set cable 3 to 5
Set cable 1 to 12
Set cable 2 to 12
Set cable 3 to 12, then 4
Set cable 1 to 3 (1 notch below cable 3)
Set cable 3 to 7
Set cable 2 to 0

Cutscene Skipping

There are two types of skippable cutscene in Revelation, those you can skip with spacebar, and those that don't freeze you in place. These latter cutscenes aren't numerous, and managing to skip them instead of waiting them out saves a fair bit of time. The most significant ones are, in order:

Opening the linking chamber in Tomahna. Looking down and left after pulling the lever just gives you access to the node behind you, and when you move there, the link chamber will be open, letting you walk in sooner than waiting for it would let you.
The rockship in Spire. This is very tricky to skip, as the game forces you to look at the rockship. However, you can still move the camera, and the hotspot to go down the ladder is active, so it is possible, with practice, to click the hotspot as the camera swings past it. If you miss it, you can also flail the camera back towards the hatch and try to click the hotspot. If you get it with either method, you can zip back to the dock control panel before the rockship cutscene would normally end.
The swinging bridge in Tomahna. This one can be done both times the bridge is swung, by stepping behind you after pulling the lever to swing the bridge. Much like the linking chamber, the bridge will be in place, letting you cross.
The harvester in Serenia. This can also be done after every pull of either lever. Simply step towards the right after pulling the lever, and then come back.

The Memory Puzzles

This is a minor optimisation, but instead of memorising which image to move to for each step, you can instead memorise which way to move the camera and how far (e.g. for the first memory puzzle, the first step involves moving from the chessboard to the figurine; this can instead be "one turn left"). The sequence of moves when framed this way is as follows: