We have the 2100 and carry folding chairs. How we carry them has gone through several phases.
First we had 2 zero gravity chairs and purchased hooks that attach to the ladder. They worked well, but several things I tried did not work to keep the chairs clean and/or dry. Clean and dry was important because we also used one for husband inside for watching TV/movies. The one we have (which is one of the smallest made because we are small people) fits great between couch and dinette when slide is out.
I was not fond of the zero gravity chair. Husband loved his. For me we purchased a very light weight compact folding directors chair. (Currently in storage so can't tell you more. It will fit in back storage area, under dinette when traveling or shower stall.
The final resting place for the zero gravity chair while in transit is in front of kitchen bungee corded to the knobs. It is not in the way to get in/out at the rear door, stays dry and clean, and is very handy if we want to use it for a mid-day lunch stop--which we have done. We traveled for two months from Colorado, through Alaska and home again and that is the system that worked for us. Even took the zero gravity chair into our cabin on the ferry. Husband would not want to be without it.
As to other exterior storage....
We purchased a 2100 because we wanted SHORT for driving, parking, camping in national parks and BLM land where short is frequently necessary. Adding a hitch storage box would defeat our goal/purpose.
On some trips we bring an inflatable kayak. When a couple days trip to the destination, we have hoisted it on top and lashed it down. It only weighs 35 lbs., but a challenge to get up and down. When just a day trip to destination, it sits in the aisle.
If you want other information on ways we have minimized/downsized to fit all we need in the 2100, send a PM.
Nicki......Glenwood Springs, CO