I saw something like this on a friend's trailer.
This isn't my idea, hope it's not patented.
The intent is to provide a latch to keep the jack wheel from dropping during towing without having to remove and stow the jack every time. I liked that idea, so I took a picture of it, sketched out what would theoretically work, cut one out of wood, made that actually work, fixed the sketch, and cut the steel.
This worked on my trailer, It may not work exactly on yours, but if you cut it out of wood first, you can make adjustments, if you need/want to, before cutting the 304 SS plate.
Why Peek washers. Well, friction washers are expensive for some reason. And, based on my experience with ball valve torque requirements for Peek vs. Teflon. Peek is very frictioney.
The hole in the AL-Ko jack clamp is already there, it's just a wee bit too small for a 10mm bolt, and it's not quite small enough to tap it M10 x 1.5
The attached should get you off to a good start should you desire one of these on your own trailer. Feel free to improvise, or you can tell everyone else the correct way to do this, or share your knowledge of why this is such a bad idea. It's currently snowing in SC, so not much else to do today other than instigate another online incident.
SF