Took one last look at that problematic coil mounting post on the engine block. Heated it up and part of the aluminium fell off. I was surpised to find that someone had already tried to put a 4mm stud in. They seem to have ran out of luck gluing the post back on and they must have drilled out or stripped the threads in the aluminium.
Because the stud seemed secure enough, I went adhead and made an aluminium stand off using some scrap aluminium rod. I am a bit disappointed with the job they did with the stud, it has a bit of flex, which may or may not be an issue. I probably would have gone with a 5mm stud for rigidity, flattened the rough aluminium where it broke and then tapped the threads. Didn't want to try removing the stud, because it might do more damage and I am not 100% sure that it is glued or screwed in. I know the whole engine it is only worth $20 but it seems a shame to throw away an entire block, considering the bore is in really good shape. Here are the results: