Touchpad on XPS far too sensitive on Ubuntu

I've installed Ubuntu 20.04 on my XPS15 (model 9560) and am having big problems with the touchpad being MMUUUUCCCHHH too sensitive. It's sending clicks and drags that simple aren't happening resulting in it being almost impossible to type any text with it self-destructing in a series of phoney drags and clicks.

The Ubuntu docs mention this for a Synaptics touchpad (which I think is the case) and describe a fix here: https://help.ubuntu.com/community/SynapticsTouchpad

But my setup does not seem to use the Synaptics drivers, so I asked here but had no responses in almost 2 weeks: https://askubuntu.com/questions/1239877/touchpad-sensitivity-on-dell-xps-using-ubuntu-20-04

My devices list as:

$ xinput list
⎡ Virtual core pointer id=2 [master pointer (3)]
⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)]
⎜ ↳ ELAN Touchscreen id=12 [slave pointer (2)]
⎜ ↳ DLL07BE:01 06CB:7A13 Mouse id=13 [slave pointer (2)]
⎜ ↳ DLL07BE:01 06CB:7A13 Touchpad id=14 [slave pointer (2)]
⎣ Virtual core keyboard id=3 [master keyboard (2)]
↳ Virtual core XTEST keyboard id=5 [slave keyboard (3)]
↳ Power Button id=6 [slave keyboard (3)]
↳ Video Bus id=7 [slave keyboard (3)]
↳ Video Bus id=8 [slave keyboard (3)]
↳ Power Button id=9 [slave keyboard (3)]
↳ Sleep Button id=10 [slave keyboard (3)]
↳ Integrated_Webcam_HD: Integrate id=11 [slave keyboard (3)]
↳ Intel HID events id=15 [slave keyboard (3)]
↳ Intel HID 5 button array id=16 [slave keyboard (3)]
↳ Dell WMI hotkeys id=17 [slave keyboard (3)]
↳ AT Translated Set 2 keyboard id=18 [slave keyboard (3)]

Note the touchpad is lists as 'DLL07BE' not 'Synaptics'.

I colleague of mine has  a XPS 13 with ubuntu 18.04 as shipped by Dell, and his devices are listed as:

$ xinput list
⎡ Virtual core pointer                     id=2 [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer               id=4 [slave  pointer  (2)]
⎜   ↳ Telink Trust Wireless Mouse              id=10 [slave  pointer  (2)]
⎜   ↳ CUST0001:00 06CB:76AF Touchpad           id=11 [slave  pointer  (2)]
⎜   ↳ SynPS/2 Synaptics TouchPad               id=15 [slave  pointer  (2)]
⎣ Virtual core keyboard                    id=3 [master keyboard (2)]
    ↳ Virtual core XTEST keyboard              id=5 [slave  keyboard (3)]
    ↳ Video Bus                                id=6 [slave  keyboard (3)]
    ↳ Power Button                             id=7 [slave  keyboard (3)]
    ↳ Sleep Button                             id=8 [slave  keyboard (3)]
    ↳ Integrated_Webcam_HD: Integrate          id=9 [slave  keyboard (3)]
    ↳ Intel HID events                         id=12 [slave  keyboard (3)]
    ↳ Dell WMI hotkeys                         id=13 [slave  keyboard (3)]
    ↳ AT Translated Set 2 keyboard             id=14 [slave  keyboard (3)]
    ↳ Telink Trust Wireless Mouse              id=16 [slave  keyboard (3)]

Note the touchpad is listed as 'Synaptics', but that there are 2 touchpads listed, unlike my case.

I've gone over the relevant bits here: https://www.dell.com/support/article/en-uk/sln308258/precision-xps-ubuntu-general-touchpad-mouse-issue-fix?lang=en

Mostly that involves adding the extra properties listed in point 8 as the other bits are not relevant, but that did no make any improvement.

Any thoughts on how to get this working? The 'Synaptics Finger' bit in the suggestions from Ubuntu seem on the right lines, but don't seem to be valid for the drivers that are in use.