7.62x39 mags for 6arc?

[VASCAR2]

CPD/Duramag list their 6.5 Grendel mags as 6.5 Grendel/6 MM ARC. Alexander Arms say their E-Lander mags are optimized for the6.5 Grendel and were not reliable with 6 MM ARC. There are mixed results on whether 7.62x39 mags work reliably with the 6.5 Grendel. There are mixed reports of 6.8 SPC mags working with the 6.5 Grendel. In my opinion there is no consensus on either x39 or 6.8 being reliable in every 6.5 Grendel
AR-15.

I think I’d try CPD/Duramag 20 round 6.5 Grendel first then some ten round 6.5 Grendel mags.