There are always pull down exterior window awnings for the side windows like these.
SL Window Awning - Carefree of Colorado
Over the years I've seen hundreds of motorhomes with them. We have never installed them. In most cases we pick a campsite where the setting sun is on the passengers side of the coach. As the sun gets lower in the sky and starts beating in the windows we extend the patio awning.
As for the valve stem extensions we chose not to put them on our 2013 Adventurer. We had them on our 2001 Adventurer with the TPMS senders. Even though we used solid brass extenders they started showing wear spots where they rubbed against the rims. Some manufacturers make either a plug for the outer wheel or a bracket to hold the extension rigid, but we couldn't find any that would accept the profile of the extensions we needed.
To air up the inner duals I modified the chuck for the air compressor so it fits through the outer wheel and onto the valve stem on the inner wheel. I used this chuck (note the configuration of the foot that fits the valve stem).
SL Window Awning - Carefree of Colorado
I replaced the brass tube between the rubber hose and the foot with a piece of 5/16" steel brake line. The brake line is strong enough to withstand the pressure, and can easily be formed to the necessary profile.
I install the TPMS sensors on the inner wheels by slipping my hand between the tires and starting it on the valve stem. Then I use the wrench that was included in the set to finish the job. It isn't the most convenient, but it eliminates the extension and there's less chance for failure.