Currently, post 1 Jan 2026, I believe EU and UK class marks are aligned. What happens after the end of 2027 is unknown.
I’ve no idea on eu airspace regulations so won’t comment.
However unlikely, it means that if something goes wrong and authorities get involved, after market accessories fitted to a class marked drone would take it outside of the classification system, which might void any insurance and would certainly...
Here is the relevant section of the drone code on the CAA website.
https://www.caa.co.uk/drones/getting-started-with-drones-and-model-aircraft/drone-code/where-you-can-fly-points-3-to-9/