My professor friend hasn't helped much yet - said he wanted to think it over and work on it and will get back to me.
I re-read the installation and assembly instructions I had downloaded for my Reese Pro-Series hitch and there's a note that says "some applications may require a longer shank ... shanks of various sizes are available separately." So a longer shank is endorsed in writing!
I also checked with the power tongue jack manufacturer about rotating the jack. The answer is no.
I took it over to my local VIP Auto store. They took out the short shank, installed the longer one, and tightened the two 3/4" bolts to the required 260 ft-lbs of torque (it took two guys to do it). No charge! So I'm all set to go for my next trip in three weeks.
Thanks again for your information.
2013 Flagstaff UltraLite 23FB
2012 Dodge Durango Crew 5.7 V8 AWD