# wsconsctl mouse1
mouse1.type=ps2
mouse1.reverse_scrolling=0

# wsconsctl mouse2
mouse2.type=usb
mouse2.rawmode=1
mouse2.scale=0,0,0,0,0,0,0
mouse2.reverse_scrolling=0

# dmesg
[...]
uhidev2 at uhub1 port 2 configuration 1 interface 2 "Microsoft Microsoft Nano Transceiver 1.1" rev 2.00/3.15 addr 2
uhidev2: iclass 3/1
ums0 at uhidev2: 5 buttons, Z dir
wsmouse2 at ums0 mux 0


xinput doesn't change after plugging in the USB mouse:

# xinput
⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ /dev/wsmouse0                             id=7    [slave  pointer  (2)]
⎜   ↳ /dev/wsmouse                              id=8    [slave  pointer  (2)]
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ↳ /dev/wskbd                                id=6    [slave  keyboard (3)]

# xinput list-props /dev/wsmouse
Device '/dev/wsmouse':
        [...]
        Device Accel Constant Deceleration (278):       2.000000
        Device Accel Adaptive Deceleration (279):       1.500000
        [...]

wsmouse and wsmouse0 are the same. And the values are effective for the internal AND the usb mouse

The usb mouse should run with these settings:
# xinput set-prop /dev/wsmouse "Device Accel Constant Deceleration" 2
# xinput set-prop /dev/wsmouse "Device Accel Adaptive Deceleration" 1.5

The internal mouse (navpoint) should run with these settings
# xinput set-prop /dev/wsmouse "Device Accel Constant Deceleration" 0.4
# xinput set-prop /dev/wsmouse "Device Accel Adaptive Deceleration" 1.2