Taking a clue from this, I realized the problem is not in the mouse, but rather in the system. So I’ve changed from the Apple Bluetooth Adapter driver (installed by BootCamp — my version is 3.2) to the Generic Bluetooth Adapter driver and now the idle wakeup delay is minimal, barely noticeable.
To do this:
- Open the Device Manager (Start | search for “Device Manager”)
- Expand “Bluetooth Radios”
- Double-click the “Apple Bluetooth Adapter”
- Chose the Driver tab
- Click Update Driver
- Select “Browse my computer for driver software”
- Select “Let me pick from a list of device drivers on my computer”
- Select the “Generic Bluetooth Adapter”
- Click OK and wait while it installs. It might take a little time, but in the end, all of your Bluetooth devices should be available.