I have a 2016 17RD, I've done a couple of small mods and one, at least for me, bigger mod.
The biggest one was adding a cabinet for hanging clothes and downsizing the queen bed to a 3/4. Since its just me and my two little dogs a queen sized bed was just wasting a lot of space and I had to crawl on the bed to reach the front cabinets.
My plan was to add a cabinet to the left of the window where you see the light on the wall. I was also going to move the base of the bed back about a foot for the new 3/4 mattress and gain a little more floor space.
Some during pics
I have to move the pump and am going to add a little accumulator tank to the mess while Im at it probably mount the pump on an old mouse pad or something while Im at it.
The little night stand is easily removable to access the water heater. I added a 12v port above the top shelf for phone charging or my fan. Im really excited to go camping and try this out.
Other mods I have done.
I changed out the light over the dinette for something a little nicer.
Upgraded to two batteries and propane tanks.
Electric jack too.
Probably the best was upgrading to 15" wheels and Goodyear Endurance tires with around 2000 lbs load capacity and an 87 mph speed rating. I wont ever drive that fast, usually 65-68 is where I end up. Just having a little more cushion is all I was after, sure tows nice too.
The future may include some solar and better batteries.