This is a classic case of our intrepid regulator making it up as they go along. A Microlight FI has no capacity under the EU Regulations and therefore does not meet the requirements of FCL.910. It doesn't matter what the CAA says, it is not legal. You say, "apparenly the CAA agreed", do you have that in writing? If not, it is merely hearsay and has no validity at all. I doubt that anyone would be prepared to put their name to such a statement, but in this day and age nothing would surprise me. As HoT you operate in accordance with the regulation and you are home and dry. Anything that appears contrary to the regulation is exactly that. Put simply, there is nothing to resolve, your Microlight FI is not even in the loop.