Portable setup WIP; Anyone else with a Lightrack II mount?

[Notty]

I've been working on this portable setup to try and maximise my chances of getting any AP done during when working away from home.  It's essentially a DSLR / Lightrack II system, and I've even found a way to attach my QHY mini guidescope with the QHY5L-II.  I plan to control it with a ridiculously cheap (£120 brand new) Chuwi Win10 tablet which I chose because it has 2 USB ports; (1xUSB 2 and 1x USB3), and a small power tank.  I'm waiting for an illuminated polariscope with 90 degree prism for ergonomic PA.  It's a work in progress and the weather has left me zero chance to play with it this week as all the bits and pieces have been arriving, but I wonder if anyone else has this and mount and  it up for guiding from PHD2, if so, I could do with some advice.  The only port on the mount is a 3.5mm ST4 and it came with an RJ11-3.5mm ST4 cable.  I therefore have USB-QHY from the tablet and the ST4 from the camera to the mount.  Would the correct "mount" to select from PHD be "On Camera"?  Anything ASCOM-ey I try and chose obviously throws up an error as EQMOD tries to detect a mount and fails - is this expected on this kind of setup?  I'm only used to EQMOD pulse guiding so this is a new approach for me.  Thanks for any tips.