On the clients page we have the "Capable Wi-Fi standards" that indicates what the client can do. But I donÄ't think that we really can conclude that the actual connection is ax or ac. But it the client is capable of ax, it typically should be connected with ax.
What I am missing more is the information if the client used WPA3 or WPA2 if I have enabled both on my SSID. Without this information I have no idea when it if time to really disable transition mode.