If the radio is properly aligned, then pushing it for MAX output will shorten the finals lifespan. Wringing the last watt out of the radio will not make that much difference on
the other end of a contact. If your radio does 100 Watts with no overheating issues, then
leave it where it is. If you are wanting more wattage, then consider a good amp.
But, on 11 meters, 100 watts should be more than enough to be heard when conditions are right. When they are not, then no amount of power will be enough!
Good luck and pay attention to your tech he is telling you right.
trucker