Supermoto's run "tubeless" tires with tubes in them all the time. They also run air pressures way lower then you would to generate extra heat.
Again, putting a tube in a tubeless rim/tire combination, other then being stupid, is not going to cause any issues. It has been done in the past for various reasons by more then a few people. There is nothing special about the tire/rim of a Guzzi that makes it a problem. But what does it matter as you now know it has been done and I would assume while you are fixing/tightening the spokes you will be removing the tube.
Again, sorry your dealer is not taking the initiative and fixing the wheel. But how you are staying calm and letting them put you off is beyond me. I would have already lost it in your shoes.
Best of luck.
Again, putting a tube in a tubeless rim/tire combination, other then being stupid, is not going to cause any issues. It has been done in the past for various reasons by more then a few people. There is nothing special about the tire/rim of a Guzzi that makes it a problem. But what does it matter as you now know it has been done and I would assume while you are fixing/tightening the spokes you will be removing the tube.
Again, sorry your dealer is not taking the initiative and fixing the wheel. But how you are staying calm and letting them put you off is beyond me. I would have already lost it in your shoes.
Best of luck.