@ZeroWithSlashedO
Never mind, by some miracle I finally got it lined up so it opens and closes straight, changed the dimensions a bit. It rotates along the hinge too, just had to connect from the door to the rotator instead of vice versa.
Once again, I really appreciate your help. Thank you so much, I'll definitely give you credit for helping when I upload the plane.

@ZeroWithSlashedO
I tried to do all the steps you mentioned, unfortunately it's still having problems. For some reason it acts as if the rotator's attach point is at the middle of the hollow door piece (because hollow fuselage blocks only look hollow) and even if I autoconnect it still does that and rotates the whole thing from the middle instead of working like a hinge. Tried to connect it to the middle first and then position it after, no change.
I made it massless, tried using the base nudging mechanic to rotate it but that didn't work for some reason, registered Y and Z as the same axis (very odd).
Another strange issue is that disableBaseMesh didn't get rid of the base model on the rotator (I put "true" as the value)
But one good thing, the delay command works!
I'll keep playing around with this, maybe I'm missing something, doesn't seem like it though.
Thank you very much for the directions, I definitely learned a few useful things.

@ElevatorEnthusiast747
Ah. I understand now.
For that, you don't go to the multi edit tool.
Here are the steps for making a perfect gear door using fuselage cutting:
Step 1:
Cut the pieces to your desire.

Step 2:
Get another fuselage piece, recommend the hollow ones. Position it, match the block with what you want to have the doors on, and cut it. Don't forget to make it massless.

Step 3:
Grab a small rotator, make sure it's facing forward, put it on the doors, position it to be at the tip of the door, and auto reconnect it. If you have problems with reconnecting, nudge the rotator and the doors down far enough from any block, reconnect the back of the rotator to any of the fuselages (do not auto reconnect), make sure that the rotator is positioned behind the doors, and then nudge it back to where it was.

Step 4:
Set up your rotators. Add disableBaseMesh to your rotator to get that annoying base model out of the way.
What style do you want the gears to have?

Style A: Delaying after the gear is up/down

• Select the rotator (if you're using multi edit, select the doors as well, or if you're using the base nudging tool, you can go to the part where it says "Selected", and tap it), rotate it about 90° in Y (if you're using fine tuner and you want it to rotate the other way, then use "320" in the Y, or -90 if you're using the base nudging mechanic), and put this in the input:
  floor(smooth(clamp01(LandingGear), 1/X))
  X being the delay in seconds.

Style B: Open only when the gear is moving.

• For this, you don't need the complicated rotating part, and it's much cooler.
  You just need to put this input:
  ((clamp01(smooth(clamp01(LandingGear), 1/X)) < 1) & (clamp01(smooth(clamp01(LandingGear), 1/Y)) > 0.025))? 1 : 0
  Here's one problem though... I don't know what the X or Y do. But basically, set it up to your desire.

Step 5:
Profit.

@ZeroWithSlashedO
The multi-edit tool doesn't rotate objects along the direction they are facing.

@ZeroWithSlashedO
Sorry if I'm being obnoxious about this, but I've never made custom landing gear before, and I'm relatively new to making complicated planes.

@ZeroWithSlashedO
I just don't get why this cylindrical ikea cabinet has to be so difficult. I built the wings and fuselage, I made the wheels, this is all that's left really in terms of structure. Honestly this is harder than actually getting a build to fly.

@ZeroWithSlashedO
https://www.simpleplanes.com/a/0N4t32/Door-Help
Trying to make this work properly.

@ElevatorEnthusiast747
I don't understand.
Okay, let me translate this a little bit:
So what you're saying is: "it works, but it faces the opposite direction of what I want it to face"?

@ZeroWithSlashedO I tried that and it definitely helped, but when I try to rotate the rotator (so its neutral position is open), it doesn't rotate it on the axis of the direction its facing. If only SP had a way to change the axis of rotation, so I could turn something at an angle. If that makes any sense. I set the min to -1 and max to 0 but it still has to open at spawn, so I realized I might have to rotate the whole thing to the open position, and that didn't really work due to the axis still being straight, and not at the angle the door is on the rotator.

Hmm... I guess set LandingGear to the door bay rotator's input, then put "max" at 0, and the "min" at -1. If the direction is reversed, just invert the rotator. Not by rotating the rotator, but by inverting the input of the rotator. Though rotating the rotator also works I guess.

@ColonelCanada It's something else

@DeveloperKorzalerke Never knew about that useful trick before, thanks a lot. That solved some problems, but the main problem is trying to make the doors in the open position already in the designer, so they don't have to open when I spawn in. Seems like that would add more realism so the doors don't just glitch through the already extended gear.

@ColonelCanada Oof, i got roll ricked

@ElevatorEnthusiast747 If that was an attempt at a rick roll, it was a failed one.

@ColonelCanada

https://youtu.be/BGJhpeqn_6I

Use !Whatevertheoriginalinputwas as the input, that should make the rotator activate if the input condition was not met.

@ElevatorEnthusiast747

komedy=yes

@ColonelCanada >komedy

This answers your question