Sorry, bevel or chamfer would have been better terms.Taper?
if you mean it's bolt holes had a machined stepped recess? they're made for the head of a standard chainring nut to sit in, Simply flip the ring over so the flat side is against the spider and the bolts sit in the recesses. The renthal logo will face inwards so be hidden but the ring will work fine. Saint M820 rings have the writing on the other side.
IIRC Saint 820/825 cranks did have a very slightly thicker spider than 810/815. (But those never had covers)
Shimano used similar *style* bolt covers on XTR double chainsets and their higher end (Ultegra/DuraAce) road chainsets. But I'm fairly sure the road versions wouldn't fit with the Saint spider profile at all. XTR had a different BCD to Saint so I wouldn't have thought they'd fit either.
Yeah I know a small section will drive it but being fat and lazy I have killed some chain ring nuts in the past when they came loose.