I believe you are correct. The Apex does still have the internal rubber damper on the output shaft.
There is an awareness in the Yamaha community that these engine/redrive setups are not proven. In fact, when somebody shows up on the Facebook site wanting to put one in some super whiz-bang model like a BD-5, they are usually told that the engine is unproven in aircraft and should be installed in an airplane that is capable of making an off airport landing. However, so far the engine/redrive combination has a good record. Time will tell!
To Marc W: In your post of Feb 19,2020 you attached cover to aluminum plate that was chucked up in lathe chuck. You then got a better centering by using chuck jaws ( 4 jaws I guess). I am guessing that the chuck jaws secured the plate in a hole that you drilled in the plate that was roughly concentric with the cover hole. Does that sound right. Thankyou
The plate has a block screwed to the back side. It must have been a jig or fixture in a machine shop. The other side is chewed up and full of holes. I don't remember where I got it. It's been in the scrap pile for years. I trimmed the plate to fit the swing of the lathe and clamped the block in the 4 jaw. This is why I never throw anything away! A man's wealth is measured by the quantity and quality of his junk!