We had similar dealings with flying over from Black to Caspic Sea. Grid MORA over 14000 a lot and it had been suggested here that custom made maps may be provided with higher density grid so you do not get a 60x30 NM large chunk of airspace blocked when it is not necessary.
Further investigation revealed that you can actually cross the area in FL 100 on airways so luckily we've avoided all the stepped descent scenarios.
I know our big colleagues cross Iran/Pakistan only with these scenarios but still they definitely have more than 12 min. I wonder if the denser grid would be of any use such area.