This is a gyro based auto-climb & altitude holder (wing leveler). Gyro will try to stay near the target altitude. You can lock target at your current altitude, and also adjust target between 0-15,000m.

Feel free to use this on your project, just give this a credit and put a link to this page in the description.
If your plane is heavy, change gyro's Stability and Speed appropriately (in overload). On my 22,000kg jet for example, I had to increase these numbers to around 20 (2000%) stability and 4.5 (450%) speed for it to work properly.

Based on Aweyer26's memory rotator (link) that uses smooth function to store numbers.
With my current level of funky trees mastery, of the knowledge of funk, I wouldn't have been able to make the "set it to current altitude" thing possible without it.

FT might break if you simply save these rotators as sub assembly. If that happened, get a new rotator and copy paste the FT to your new one.

AG 1 to enable gyro
AG 2 to "lock" target at your current,
AG 3 to enable custom target setter (use trim to adjust target). *Make sure AG2 is on when you use target setter. Coulda improved control.

(Explanation of the memory rotator, unfortunately images in the post seem to have expired: https://www.simpleplanes.com/Forums/View/1422414/How-to-store-and-utilize-memory-in-Funky-Trees)

Used a modified version of non-linear input FT from FunkyTreesStuffz by PilotOfFuture (link) to control the target altitude setting rotator (I call it TALTator). Really useful FT (thank you, if you are reading this) There might be a better method for setting target altitude than with trim though, I'll have to think about it.

Inspired by RadarJamJar's Autopilot FT (link). (Really cool stuff, check it out) I wanted something similar to that (alt hold/wing leveler in particular) so I don't have to manually maintain altitude on a long flight.

This is an advanced version of my earlier Altitude Hold Gyro Mk1B (link)