This is probably a stupid question but here goes.
I’m putting up 1×3 strapping on sloped and flat ceilings. I’ve been using #9 2 in GRK R4 wood screws in pairs wherever a strap cross a rafter. These seem beefier than they need to be. I only ever need to shim things by 1/8 in at most. The rafters are old and I don’t want to abuse them any more than I need to. I’ve got #8 1-1/2 in GRKs but these seem too small. I can get spax #8 2 in screws. Do I need the #9 2 in or is that overkill and I should go smaller?