I have a Gardyn 3.0 and 4.0.

They run Raspberry Pi OS with some custom code.

They have live access to the cameras.

Were you able to disable their remote access software once you were poking around the raspberry pi?

I could've uninstalled the package, but I moved it all to a separate VLAN until the warranty is over.

I'm debating writing a custom firmware, the GPIO pins are documented somewhere.

  * Run pump. 
  * Turn lights on / off / %. 
  * Measure water in tank. 
  * And then they have a moisture / temperature which they use for their 'AI' / heuristics on whether to water more or less. You don't need that. You just water more often. The point of hydroponics is that the roots sit in water. 
  * Occasional photo (via USB). 

I'm trying to find a Raspberry Pi Zero 2 W with the GPIO pins soldered on the 'other side', as that is how the Gardyn is setup.