Hi Paul,
regarding hex tiles being not suitable for structures that block – Have you thought about hex tiles that simulate dangerous depth? Like tiles for canyons, holes, and so on.
I guess it definitely would add something to the game to shield bash enemies into a pit. A large structure that could help this feel would be a bridge.
Cheers, looking forward to more (very old player that is returning with the latest great news of the DLCs!!! Keep em coming!)