I put it on an insulated coffee mug to get off a sticker and it ate the plastic. Goo-gone is less invasive. Royalex is a type of plastic.
As noted, with any remover, try it on a small inconspicuous place first.
Using some type of sharp knife or scalpel, carefully, to remove the upper sections first sounds like a doable option. I've done this with other items but not royalex.
Touring Kayak Paddles
Overstock Outlet Foods
URCHIN Portable Anchor
Kayak & Canoe Covers
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