Just some observations on the "engine movement" issue.  As I was building I did some analysis of the engine mount system and compared it to that used in the Lycoming engines.  I suppose the idea behind the so-called dynafocal mounts is that the stiff orientation (in the axial direction) of the mounts are all directed, or focused, to a single point.  The "soft" orientation of a mount is in the lateral direction.  The net result is that the engine can move freely (well, more freely) in any direction as long as the point that is in the focus of the mounts doesn't move.  Imagine the mounts being just greased plates so you could swivel it all around.  Problem is that in the Continental system the focal point is well BEHIND the CG of the engine/prop assembly.  So the weight of the engine will easily pull the nose down.  The Lycoming configuration (for the 6 cylinder engine - I don't know about the 4's) the focal point is either at the CG or the prop flange depending on which of the two mounting systems are used.  And the Lycoming mounts are spread widely apart compared to the Continentals.  Another secondary issue is that as best I can tell the Continental mounts are focused (incorrectly) on the crank centerline instead of the CG, which is lower.  But I don't know whether or not that contributes to the problem. I don't know of a solution short of changing the orientation of the mounts.  The engine CG is essentially over the front mount, so it should be pointed more or less vertical in the side view and the rear mount angle more forward.  I would be tempted to even point the front mount truly vertical, compromising the focus, but giving it more stiffness in the vertical direction.  So how about reverting to the old non-focused mount in the front and leaving the rear alone.  I'll bet the sag would be less, although perceived vibration might be more.  Just some random thoughts from a would-be engineer.

Gary Casey