I get to say it at least once. Told you so...

The Caps are the most fragile thing in the ecu. Mitsu went cheap here. Unless the circuit board damage is worse than it looks, I think I'd just have the caps replaced and the board cleaned up well, then test function installed. Good luck with it. I think the mech can quit looking for the relay. I don't say it can't fail, but I don't remember many that did.

Not responsible for advice not taken...