Mid-Air Returning Platform (Expandable)

Updated version (with infinite fly height): • Mid-Air Returning Plat...
Expandable (width/length and height to some degree) mid-air returning platform
I'm not sure if there are any uses for this besides a 3d hipster door (self-building house) but I'm quite proud of the design so I thought I'd make a separate video on it.
Features:
- Expandable in width/length
- Expandable in fly height to some degree (will require additional modules beyond +- 35 blocks in height)
- "Instant" returning platform
- Compact layout
- Ability to push blocks (with solid layer on top)
- Ability to retract blocks (slime/honey on top)
- Low minimum fly height
- Can stop/return at any level
The mid-air returning is done by using a fast (10gt) engine that stops the slow (16gt up/10gt down) platform after which both flying machines hit the push limit making them return.
The improvements over the self returning platform that I used for a recent 3d hipster door is that this version returns instantly, it's expandable, it has a lower minimum fly height and a higher maximum fly height.
Some of the challenges were the following:
- 16gt up/10gt down engine return mechanism that fits within a 2 wide space.
- Preventing modules that are unreachable by redstone wire to collapse (the return flying machine stops the platform, hence the terracotta layer).
- Preventing the stopper flying machine from triggering the platform flying machine to early.
In the end I had to use a directional layout as it meant I could place obervers in between the engines.
This leaves the following improvements:
- Non-directional design
- Infinite fly height
For a 3d hipster in particular, there's another requirement to push the platform up 3-5 blocks while returning the platform manually.
This is needed for fast removal of layers from the platform ( • Minecraft 8x8x8 Self-B... at 3:49)

[@levipurves5980]

I mean, it could be a good way to impress people by using that system to put a roof on a house, but seriously, that's insane! The biggest flying machine I've ever made was a tiny elevator 😆 Not really my forte :)

[@viktorbergman517]

That's interesting, I was thinking of a flying machine that would do this, I'll probably take this concept and make one of my own, since I need it to be from the top