Yes Paulo, I am Flemish!
Although for the time being -8 months now without a new government- I prefer to see myself as a European citizen... But this is of course outside the subject of this thread.
You are also absolutely right about the Pogo 10.50 being quite slow when motoring. With 18 hp for 3.600 kg the power should be sufficient, I think the wet surface of the hull can be a reason. Being very light, there is also little inertia in a seaway.
I suspect this will not be different with the 12.50 (30 hp for 5.500 kg) which is also a very light, beamy boat with a flat hull aft.
But on the other hand, with a Pogo one is supposed to hoist the sails with as little as 4 knts of wind...