I am maintaining a collection of Hubitat device drivers for Xiaomi devices here:
I don't own the single button wireless wall switch so there isn't a specific driver for it, but since you have one I can add support for it in one of the existing drivers (either the device driver for the Aqara button or the 2-button wireless wall switch (WXKG02LM) if you don't mind testing it.
However, from my experience with the 2-button WXKG02LM and based on my research, the 1-button WXKG03LM does not support double-click or hold in hardware. It only sends one type of message, when the button is pressed. So double-click functionality would have to be "emulated" using a timer in the device handler (the code for which I've worked on in both the "original" and Aqara button bspranger DTHs for SmartThings.)