I’m gonna say that the insulation is pretty much non-existent between the electronics box and the oven… moving the heat sink to the bottom of the box may have been on my to do list still from last time, but adding a fan should be pretty easy since I think that display panel runs off of 12v… and that may have also shortened the other’s effective duty cycle as well…
This is definitely the 3rd or 4th time that relay has been replaced.