Thanks for your thoughts @Shub
All the changes that I have been thinking of are just small bug fixes and currently, all of them are in the issues or PR sections on github. I posted this question here before creating PR #1094.
If FreeRTOS+TCP was designed for routing, then it would make sense to allow reception of a packet on one interface if the packet was destined for another interface. That is wat routers do. Once I got my answer, it was apparent that what I had found was a bug so I created PR #1094. That’s all.
Again, thanks a lot!