Yeah, no worries! :)

I mean, the biggest thing they’re using is their own board, which is only that big because it includes inputs for a big range of inputs on one board instead of using multiple nodemcus, one for each sensor. And to be fair, the Pi Zero 2 WH is dwarfed in comparison to their board, in size and in price. Its 55$ and the pi zero 2 wh is 15$, which is not nothing, but not that bad. They don’t sell their kits with a raspberry and they provide their own Grow Control Application: https://gitlab.com/openhydroponics/sw/openhydroponics#introduction

I like the option of the pi for data centralization (otherwise I’d need to create a Server) and providing a Grow Flower Control app is great.

But you have a valid point, sth like a home assistant integration (on top) could be nice. If you’d use it if something about this was different and have input on more (cost) efficient solutions for an API, give the devs a message. Software and hardware are open source, just create an issue.

Looks like a cool project imo