Bob
On the HF (Condor clone) chock I cut the frame down about 12 inches so as to not encroach into the garage too much. I was anal and secured mine with large bolts through the floor and used a backup plate and washers too. I don't remove mine but wish I could with my 2 year old grandson in the rig. The rear tire plywd (24 x 30) is necessary with my 900 lbs Harley Ultra Classic. The wood box under the engine/frame also helps spread the weight too. I saw some 347tht pictures where the rear tire had deflected the floor so much that their dealer replaced and braced the floor. Do a search and you can likley find that thread here. Anyways the floor framing runs longwise in the garage which seems quite odd. They use 3 inch alum. (not steel) very light channels. Also check your d-rings carefully. I had one pull out and did some damage tot eh trailer and bike. Use all the tie downs everytime plus the chock. Also the ramp really moans when I load the Ultra. The garage area I was told only has a 1000 lbs rating so the door is almost there with the harley.
If you have any other questions let me know.