Never seen an aero bar banned from an organized ride.
I’ve always liked the Profile AirStryke. The pads are spring loaded and flip up and out of the way when not in use.
Problem with aero bars is no brake and shifting ability while on the bar. So then your going to want to upgrade to Di2 to get the little shift buttons out on the bar ends. That’s a grand alone for Di2. Plus the aero bar.