I had to drill out 2 of the mudguard bolts on my bike a while back, seized solid, came out easy enough, but i was sweating thinking of the price if the lugs snapped off!!!. Went over the rest of the bike and lubricated each thread as i got the bolts out, i gave up on a few (oil cooler brackets and a couple of others) will worry about it when i need to take these parts off in the future, but i shouldnt have to it is after all a moto guzzi.
Gary