There aren't any current plans to bake in TCP support, but you can rig it up yourself using something like udptunnel.
Related old HN comment with basic instructions: https://news.ycombinator.com/item?id=17847008
Also see: the "TCP Mode" section in https://www.wireguard.com/known-limitations/.
I feel that adding TCP support would push innernet beyond a WireGuard configuration manager and into something a bit more behemoth. I'm quite fond of the fact that innernet doesn't "touch the packets" in its current state.
That said, if a strong need arises over time it's not out of the question, and in the mean time anybody is welcome to add their own wrapper around innernet or fork it to support that.