does adding a hardwood skunk stripe go some way to preventing this or is that for something else?
The skunk stripe is just for covering the truss rod channel on one piece necks (although Fender now use it on all their American Standard necks, maple or rosewood).
Since it's quite shallow and doesn't run the full length or depth of the neck, I'd guess it makes very little difference, if any, to stability.
In fact the skunk stripe often seems to "pop out" slightly. I've had lots of Fenders where there's a tiny crack in the finish
somewhere along the skunk stripe - usually right at the rounded end of the stripe near the headstock.
(Edit: this is different from the multi-laminate necks used by many manufacturers - BC Rich, Ibanez, Hamer, Feline, Wez V etc :) - where the neck's made of three or more pieces, maybe of the same wood or maybe different woods, running the full length of the neck. That definitely does add stiffness and stability. )