

Concerning the IQ: App development and regular programming aren’t that hard. It needs some time and dedication, and willingness to learn how all these things work and tie together, but I think everyone with an average IQ could do it. It’s specific domains where you need a high IQ, like writing advanced signal processing algorithms. Or write very efficient algorithms or do detailed security audits. But App development is just moderately complex, you can get away with basic math… So I’d say it’s doable. Still needs quite some time and effort though. At least several weeks to months. And the Kotlin book I have has like 800 pages filled with information, and that just takes some time to work through. None of it is magic, though. You do one chapter at a time.
Vibe coding is overrated IMO. There are applications and clients out there for whom it’s fine if you just do a piss-poor job and throw something together, and it somehow works enough. For a lot of things it’s not advanced enough, yet.
I think pretty much any mosfet / h-bridge / motor control board with pwm should do.
If you have those 4-wire fans with a pwm input that accepts 3V3 logic, you might even be able to attach them directly to the ESP:
But that’s not all fans, I had some mixed results with that.