Ejecting plugs was primarily a problem with the earliest Ford modular heads, through roughly the early 2000's, before they introduced the three valve variant.  Current V10 designs (whether 2 or 3 valve) don't have this weakness.
Even with the early engines, plug ejection is far from universal, and ensuring that the plugs are properly torqued but not overtightened (with a torque wrench, not just by feel) goes a long ways to preventing difficulties.
Relax and enjoy your RV.  You won't have to even think about the plugs for many thousands of miles.