My understanding is, from the insurance and registration view a bolt on swim platform is not considered part of the LOA.
Back to the OP: I got the memo, but did not forward it on to my better half before we bought the Cabin

For us this first year, renting a boat when we needed it worked out fine. We always had a nice clean boat, and it ran!!!!! I wasn't digging through the tool box with a guest asking "when can we go on the boat"? Or worst..... You know I think it's the........
We had small pontoons, to triple logs with 225hp and anywhere in between; ended the season with a nice deck boat. Besides, if your friends know your renting it you often find $$$ on your dresser after they leave

What I spent all summer was close to what a years payment would be on something less than I would want to buy. And that's not counting insurance, storage, maintenance and explaining to your older sister why her husband or adult son can't drive your boat
All in all it was a very enjoyable first summer as a waterfront owner. Now that the first year "surprises" are hopefully over we will look for something to tie up to the dock. Besides my floaty toy