Its great to hear that Mentor has release a customized version of VMM that runs on Questa, Modelsim. I hope it will complie on NCsim as well. In the release we have a PDF which describes how the VMM is not compliant with ths System verilog LRM. Thats seems to be true to me, because we also faced some similar issues with vcs when we were porting the environment which was written for VCS to modelsim. We also complied VMM with modelsim with some ugly fixes just to meet the deadlines.
There are a lot of different things we found which LRM says should not be supported in SV but VCS supports. I will sortly add few examples on this. There is also a reaction from the synopsis on this and one of the synopsis author says "I’d venture to say that despite all the posturing, Mentor’s support of
VMM demonstrates the solidity and broad industry acceptance of VMM."
For the users of these methodologies its good that the different vendors support different methodologies. I hope synopis also follow the same in future. Then the life of verificaton engineers like us who needs to port the environment to different simulators will be easier.