More often than not, the custom stats of a PvP relic and a PvE relic would be identical anyway, because almost every melee character is going to cap Crit/Det to get the most bang for their buck. All other stat caps, including accuracy, can be met in both content without much need of any gear tweaking. Most of the gear carries more accuracy than is necessary, so you'd have to go pretty far out of your way to fall below the required minimum.

I'm not so sure about casters, though. For the most part, I'd imagine it's a similar situation, but I've seen the occasional healer run dry on Mp, so maybe not.