The ASIAIR (or strictly speaking, the underlying Raspbian OS) already allows the WiFi Station Mode to be steered to the 5 GHz band.
The ASIAIR itself (for some brain damaged reason, probably to make it easy on the 1,2,3 folks) only allows initial connections at 2.4 GHz. However, a wireless router that has the ability of band steering has the ability to steer the WiFi device to the 5 GHz band.
My eero mesh network does that to my ASIAIR (both Raspberry Pi 3 and Raspberry Pi 4 versions). Check to see if your router has that ability, and if your other devices don't mind being band steered. Raspbian does it behind ASIAIR's back.
Chen