Why is the storage manager requesting that the wheel be on?
I use one of those orange cones under the camper stabilizer whenever it's unhitched from my tow vehicle; especially when it's at the storage location. I've used several storage locations in the past to store a camper, and none of them ever stated they needed (or required) that the camper have a wheel on its stabilizer.
2015 Jayco Jay Featherlight SLX16XRB (TT)
2007 Ford F150 Tow Vehicle (TV)