Arranging the wiring of the chargepoint so that it happens before the CT clamp for givenergy is the simplest way to prevent GE attempting to cover that part of the load. Another option might be a separate CT clamp around feed to the chargepoint so you can detect it. Then presumably feed that into home assistant or similar.
I'm currently learning about using esphome without home assistant, to feed sensors into my own scripts, and I think that supports ct clamps. Or I think Shelly do one. (A charity shop near me had one of those OWL monitors with USB support. I was quite tempted, but didn't in the end - I already have a non-USB one as a display for HP, and I record usage through one of my Zappi's CT clamps. (Got fitted for solar, but that's not much use to me.)
I thought I'd read somewhere that Ohme was going to get incorporated into Octopus' app. Maybe that got abandoned, or just hasn't happened yet.
I guess Eon Next Drive is always a simpler option...