But with small grids why not combine classes? 3 hours at Croft for less than 10 cars was boring. I know you don't put on your events for spectators, but I would have thought it should be a consideration. Also think of the marshals stood around for a 3 hour event.
I mean combine the endurance and the GT & Production into say a couple of 90 minute races. You would let them run together for the 24hrs so why not at other times?