homeguard, originally we were going to recommend that the SSEA Rating should only allow the licence holder to hold privileges on 'Simple SEP aircraft of up to 2000 kg MTOW with seats for 4 PoB, including the pilot'. But we changed this to the more flexible 4 PoB rule as it currently stands to allow for those with larger aircraft.
I recommended to the CAA that, in order to avoid expensive, time consuming admin, it would be a lot simpler just to allow 'SEP + General Exemption' pilots not to need an additional SSEA Rating included in their licence. Fortunately, CAA legal agreed.
Where it gets compicated is if someone decides that they want to relinquish their SEP Rating in perpetuity, but maintain (for example) an old-style UK PPL. The forthcoming advice circular will describe the necessary process - but the good news is that the Authority intend it to attract no charge (apart from postage) and for the applicant to use the existing 'Inclusion of an Additional Class Rating' form available from the NPLG website. Which, incidentally, I designed.
The CAA have been extremely helpful and flexible in getting this General Exemption agreed - good to see that they are fully in favour of reducing administrative burdens wherever that can be achieved!!