[jsb5717]

Also, I think the connection of toilet to floor is more complex than you might be thinking. RV toilets don't mount to the floor the same as residential. A wax ring alone doesn't seem adequate to me. You would need to get under the toilet and replumb a residential flange to the sewer pipe. That's what gives you the bolts for anchoring the toilet to the floor and provides the correct surface for the wax ring. Again, it's doable but will require more surgery than it first seems.

Then, what about the gray tanks? IF you plumb the toilet direct to sewer would you do the same for the galley and shower systems? You would be basically converting your RV into a stationary mobile home hybrid. There's definitely a benefit to directly plumbing all systems to sewer if you plan to never move or sell the rig. But it's a bit of work.

Sorry for the continuing random thoughts...