Practicality aside, an aero frame with a traditional round seatpost wouldn't make much sense if the goal is aero.
Keep in mind the majority of aerodynamic gains come from wheels, the particular clothing choice, and having an aero position on the bike.
I can understand the rationale of wanting a traditional seatpost. Dealing with proprietary components and potential seatpost slipping issues can be annoying. Seems like the only frames these days with a round seatpost are lightweight climbing frames.
A really good middle ground would be pairing deeper section wheels with something like an Elves Vanyar, VB-177, or a Winsapace SLC.