Very doable. See my previous post where I mention Gen 1 Power Board removal.Ahh! now I understand the concern.
I was not aware the lower pcb was not serviceable. I just checked mine, and there are rivets not screws :(
However I do have a drill :) The question is this: Can that lower PCB be removed at all?
If so, it can be repaired. It is a very simple circuit. Another option might be to use the board used to repair the other style. Another option, duplicate that board.
In this photo:
There seems to be two lower boards. The yellow has screws, the white does not. What are these from?
I'm sure that yellow board can replace the white one. If not directly, with some small modification,
My control board needs only 3 things from any host to operate, +5, Gnd, and a control line for the element. The temperature sensor is supplied by a probe. So yes the board could drive a relay box, plugged in to a rewired oven. It could drive a kitchen oven. It could drive a toaster oven. It could drive a sous vide heating element. It drive run any kind of heater if there is a way to control the power element.
I built this for Gen1 only because that's what I have. The project hardware would be basically the same for any heating device I want to control. Some small tweaks to the code would allow it to work on really any kind of heater. I suspect MB uses the same config for all their units and I would likely be able to find the 3 connection points I need for any model they make without any change to my hardware. These 3 points are easy to find. I could probably find them by looking at a photo of the PCB solder side, if anyone cares to post a pic.