That sure makes mine look a bit sad! I just use chains with a hook on the end. Its not as pretty as your setup, but its quick and reliable.
Regarding the boom, I personally don't like the idea of using a lock plate to hold it up. The lugs are there, but I think it puts way too much stress on the metal when I'm bouncing around the yard. At least the hydraulics have a little bit of 'give' to take the shock out of the jarring. Sure the boom leaks slowly down but I just lift it up occassionally. A burst hose is possible but I havent had one yet, and it would be cheaper to fix than a cracked boom. (You can see the backhoe has already experienced that!). But I'm planning to add a strong webbing strap somewhere between the boom and the control area.