Went to my local hardware store and found different assortments of 1/4-20 thumb screws. Bought these for about a nickel each. The only ones that secure the forend grip really tight are the ones that match the original screws, circled in red. The other ones don't insert real tight so I returned them and bought a handy Phillips miniscrewdriver that I attached to my keychain so I guess I'm stuck with having to screw it on or off during barrel changes.
Good news is, I don't have to go to HR1871.com to buy the original screw which probably costs an arm and a leg. Instead, I have 10 spare screws now for about 50 cents! So even if I strip the cross, just throw it away and replace.