With respect to that OEM Yamaha skid plate:
While the OEM Yamaha skid plate will protect against gravel and light contact, be aware that we've had at least three owners with this skid plate who have put a hole in their sump and lost all oil.
The skid plate brackets bent, allowing the plate to push the boss on the sump pan until it broke through the pan. That's why nobody recommends the OEM Yamaha skid plate for anything more than keeping gravel from sand-blasting the bottom of the engine.
Here's one of the SA incidents:
Not a single-track road to think of as threatening to a skid plate:
They were lucky to have enough JBWeld (or similar) in the group to get home: