Interesting take on launch/retrieve
Your launch process is great. Trailer further down ramp would reduce water entering over stern though
Problem here for me is retrieval.
If I used the same rig, other boaters at launch ramps would be very annoyed at time taken to load yak back on. The guy waiting on jetty behind you was very patient
I'd have had rocks thrown at me, (maybe with luck, a full can of beer or 2) not to mention the verbal abuse, if taking that long
Also, I think you would have to organise a more effective "guide on" with your retrieval rope/ramp.
There was no wind at all, which is fortunate for making of this vid and people waiting to bring their own boat/s in. Your "rope flicking" technique to get yak into position over the ramp with any cross breeze would be pretty much impossible with your current setup
Have a look at boat trailers with "V" type guides at rear to centre the bow. You may be able to use tubing, angled down and spread to achieve an easier retrieval process
You could also seriously consider backing the trailer further into the water like most people do, up to about where axle hubs are. That way you may not need the "tube/wheel extention" at all. Just try it.....
I have a dinghy as well as yak and have installed a walkway down centre if my trailer so I can grab the bow and haul it up without even getting my wet feet or slipping over on launch ramps.
If you tie a long handling line (with a loop or clip) to a line tied between bow and stern handles it's very easy to then walk down the jetty to your trailer, then pull the yak over to load. The handling line will slide along the "bridle" rope towards the bow
You're obviously a creative person and I wish you well, and good luck.