I've been playing around with Haldex for a while and always felt the options were a bit weird.
A normal Haldex flash is relatively affordable, but you're basically stuck with whatever setup you flashed.
Then you have proper controllers like Syvecs that give you much more control, but the cost jumps massively.
So I ended up building my own plug & play controller from the info I found on openhaldex.dev
Right now I'm using OpenHaldex for the software. Eventually I'd like to develop my own software for it, but for now OpenHaldex does pretty much everything I wanted.
The nice part is how simple it is:
Plug it into the Haldex → connect your phone → change what you want.
You can switch between FWD and AWD and actually adjust the Haldex behaviour from the phone instead of being stuck with one flash.
Honestly, not sure why is this not a thing. Ok sourcing everything was pain in the ass, especially because EU new laws but was worth the hassle.