I don't know why it blew, I was just standing near it and "POP", no fluid ingress involved. Upon investigation, the only issues I can see are a blown board terminal and a glass fuse (that I removed), and a somewhat cooked and damaged power wire with only half the strands attached that is screwed onto one of the elements tabs(see pics). Looks like it has become brittle through overheating, perhaps it built up resistance over time, not sure, you might want to check your own connections after some use with this type of setup. I might try a new wire soldered straight to the PCB (where the blackened area is) and a new fuse repair and see what happens.
Might also consider adapting the Brewzilla control panel/pcb, anyone done this?
Can't find any reference to parts on KK website, what $ did it cost you Weal?