ORIGINAL: w8ye
On the DLE 55, all ones I've seen, had the port inlets and outlets internal to the cylinder and are the closed type and use a windowed piston to facilitate the air-fuel transfer. There are no ports at the bottom of the cylinder-crankcase mating area to consider. The cylinder gasket is the same, right side up or wrong side down. It is symmetrical left to right.
But the cylinder is relieved differently front and back for the rear bearing and the reed plate.
Also like several people have mentioned, there is no real mechanical reason to turn the cylinder around 180 degrees. And there is no pin offset.
The DLE55 cylinder that has been available for several years now (since they recast it) have open ports that extend all the way to the bottom of the casting though they do taper in a bit at the bottom. Even the boost port opposite the exhaust port is now open ported and the casting bridge once present at the bottom of the cylinder is now gone. As you state, there are no mating machined ports in the crankcase but I don't have an engine apart right now to view to help describe them further.