From the VDGIF website:

" Tree Stands
It is unlawful to construct, maintain, or occupy any permanent tree stand on Department- owned lands, National Forest lands, and on Department of Conservation and Recreation-owned or controlled lands. Portable tree stands, which are not permanently affixed, may be used. Use of a full body safety harness while hunting from tree stands is strongly recommended. "

Notice how nothing is mentioned here about the use of screw in steps. I have never been able to find anything in the VA Code saying screw in steps are illegal. I have used them for years, although I mainly use a climber now. Used to lease some land from a timber company and they did not allow screw in steps on their property. They said a healthy tree could handle screw in steps but they could be damage their logging equipment or hurt their employees if someone left them in a tree.