Like the others, I don't think the venting is an issue and it did not cause the failure of the circuit board. Likely, that rear vent, even with the partial blockage, vents freer than through the front.
Second, looking at the picture of the full cabinet space, the blockage appears to be the result of an assembly issue, possibly an error, but it would take another coach of the same make/model/year to know. Simply removing the wood spacer from the left side of the opening and shifting the oven over would line up the vent hole. However, as you noted, the Corian backsplash has already been cut to fit the current arrangement. Logic indicates that the Corian and cabinet opening should have been aligned further to the left. If an error was made during installation, then you have the results found in your coach.
Larry, Eileen, and Finley
2004 Alpine 36FDDS
Third motor home, first Alpine, no need for another.