but the SEP check has to be flown in SEP
That might sound logical but the CAA say it can be conducted in a 3AM and by a FI Microlight who is familiar with the requirements for a SEP. Might have been easier to just require a Prof Check. There was an AIC in 2000 detailing the requirements of the flight with an instructor but it was withdrawn after it was claimed to be too prescriptive. Here we are back at square 1, 25 years later!.