I agree to a point. Ultimate fix here would be to replace the unit with one that is properly sized. But if they are struggling with it and can't afford to replace? Then increasing the blower CFM is as far as I would go to help cool the unit. Swapping out the high limit is too risky for me. Its no different than what Enviro did to the M55. To me its the least risky and should get them to run it higher until they can afford to swap teh unit for a properly sized unit.