why don't you round off or chamfer the leading edge so it can slide a bit easier instead of having that 90 degree edge to catch the earth?

"Vini, Vidi, Velcro"

What about some hard plastic tubing that just slides over the skid tube. Cut a short piece for in front of the front skid strut, behind the up-bend in the skid and another longer piece to slide over the skid between the front and rear skid struts? The Raptor-50 has 8mm dia on the skid tubes. The OD of the plastic tubing will protect the skid supports.