Hi,
I have the Glow Worm Ultracom2 30SXI and I decided to try to upgrade to Opentherm based upon the fact that it appears to be an identical boiler to the AWB ThermoElegance 4 and the AWB 0020036768 Opentherm module is designed for the ThermoElegance 3 and 4 range of boilers. I'd seen the information on the myboiler.com site and this had triggered my interest so I took a look at the manuals for the AWB boilers and the Opentherm module. I purchased the AWB Opentherm module and it turned out to be a very simple job to install the card as all I needed to do was remove the plastic mounting frame that came attached to it as the card slid perfectly in a dedicated vertical slot for the card within 24V the controls section! The connections were simple; one plug pushes onto the X40 contacts on the control board and then the 24V connection is made to your Opentherm controller (I'm using the Evohome OT Bridge). Although your Flexicom boiler doesn't resemble either of the AWB ThermoElegance models, it does look like you have the necessary X40 port on your control board. I don't have any pictures of my installation, but I do recall that I had to remember to add the RT link (the 24V one I think) to get the system to work. Oh, and it's all working perfectly!
Here's the installation manual for the AWB Opentherm module (yes, just 1 page

):
AWB 0020036768 - 3.jpg
Hope this helps.
Dan