Double Duty Two Hander
There has been a ton of development work done on two handed rods for in-shore duty by members of this group as you likely know because you have been around on the forum for a while.
Right now all that work is being finalized into something that might become a commercial product so I think discussion about it on the board may be limited for a while.
Your question is a great question and I wanted to respond so that you understand the lack of comments may just mean the folks who were developing something for in-shore work are less inclined to discuss it until they finish their project(s)
One more comment; I'm not sure personally that a rod can perform double duty for river and in-shore work adequately. My experience is that the surf rod and the river rod need different characteristics to work well. I would encourage you to make sure your prototype testing is extensive. Best of luck in the project