Don't see shapeshifting as something beyond the scope of logias as is, but the idea of them being able to breathe life into chunks of their respective elements to create familiars capable of independent thought and action would be kinda neat. It'd be kinda like a more limited form of homie creation, in a way. Worse still, a bitch to fight if they're every bit as immune to normal applications of haki. But fuck it, all the more opportunity for Brooke to shine and contribute in awesome ways.
I don't think that'll end up being the case, but I'd welcome it.
I think the ultimate power of Awakened Zoans who can avoid going mindless is that encapsulates the concept of evolution. Awakened users would be able to take on various unique forms same as Chopper that constitute potential branching evolutionary paths and adaptations, with their most powerful transformation being that of a mythological creature or kaiju corresponding to their respective zoan, e.g. a horse zoan becoming a unicorn, Chopper becoming a Buddha lol
Other alternative ideas that popped to mind: turning objects into animals in a similar manner as infusing them with devil fruits; a lycanthropy ability that can moprh living things in the surrounding area, turning them into savage were-zoan pawns, the difficulty of doing so depending on the target's strength of will or whether the Awakened user can force the change more forcefully and direct with a bite ala a Werewolf; or maybe the Doflamingo/Robin-like ability to form or sprout animal parts out the landscape, allowing for some wonky attacks and visuals.
Yay, imagination. Give us a T-rex--> Godzilla Pokemon evolution, Oda, you son of a bitch!