No idea what your Sewer project is all about, but FWIW, one of the best mods I made to our rig, was to add a knife valve right at the sewer hose connection.
Our three tanks have their valve handles scattered here and there, with two of them over on the other side of the rig from the sewer hose connection. Means no local control over events right where you are, and no quick action if you screwed up and left one of the others open, so you are hit with a flood when you take the cap off. :(
The mod was to add the new valve, and a new cap that has the little screw-on cap. Now you can check for trouble before going all the way, and you can shut it off right now! if trouble.
Also great for filling buckets with grey water under control to be dumped if you don't want to bother moving the rig to the sani-dump just for some grey water. (or if you have a blue tote)
Add the see-through elbow to the hose so you can see when enough is enough--better than watching TV-- :) and you have your sewer situation solved satisfactorily so to speak.