I actually found that we didn't use the rear rack at all and took it off. It actually got more in the way of accessing the hot water heater. And, when weight is always a concern, the rack and pins weigh 78lbs alone.
Point is, if you find yourself not using it, take it off. That will leave you a lot of bumper space to put the spare.
2017 Forest River Surveyor 247BHDS...
...Tugged by a 2016 F250 XLT FX4 SuperCrew, Shortbed 6.2L, 4wd, 3.73...
...Joined with a Husky Centerline TS 800-1200lbs WDH