I have never unhooked before backing either. But I might start. I installed my brackets just as described. But I often see the brackets twist when I've had to make a tight backing maneuver. This results in wear between the bars and the L-pins, which in-turn causes more friction, which causes more wear, etc, etc. I ended up replacing my L-pins, sanding/painting my L-brackets and bars, and installing the L-bracket-jackets. Performance is still terrific, but I want to keep things nice.
The only real problem is waiting too long to disengage. You don't want to be blocking traffic in front of the site. So I may start disengaging while I have my daughter fill the fresh water tank at the park entrace.
thebrakeman ('70), DW ('71), DD ('99), DD ('01), DD ('05)
2004 Surveyor SV261T (UltraLite Bunkhouse Hybrid)
2006 Mercury Mountaineer V8 AWD Premier
Equal-i-zer WDH (10k), Prodigy Brake Controller