OP here to close the loop.
ALFA's home office confirms this new exemption excludes pretty much all water damage regardless of cause. Even if it is caused by a covered event like floods or impact. More risk than I am willing to assume.
This morning I bought a stand-alone TT policy from Progressive. Price was competitive but I spent a few bucks more for options they offered that I didn't have, like liability coverage at the campsite. They handed me the 42 page contract with my credit card receipt, so there should be no surprises.
As some of you have pointed out Progressive DOES exempt mold, mildew, wet deterioration, etc. HOWEVER, those exemptions state that such loss WIL BE COVERED if it is caused by another event that is covered (like an impact or a flood). That's reasonable.
