The chemical elements in flips that affect coins are NOT the same ones that react with red (typically vegetable dyes) that are used in ink and powdered dye.
What is safe for chips is not necessarily safe for coins and vice-versa.

The subject being discussed here is chips bleeding.

You stated
"This usually does not happen with NON-PVC flips, which are much stiffer than the softer pliable flips."
That is totally incorrect. The softer flips are either polyethylene, mylar, or PVC with chemical additives.
The stiffer flips are pure PVC!!!!