If same subnet is used on both Logical switches and they have no connection, then it is not possible to send any kind of traffic Unicast, Multicast or Multicast. Also it is not possible to send traffic through DLR or Edge because LIF interfaces should be seperate subnets.
If Multicast traffic needs to be sent between those (and duplicate ip on both sides is not used), then one of the Vxlans could be taken to Vlan based port-group and bridging could be used, but this is more or less the same as merging the two Vxlans to a single VNI.
Multicast routing on Edge and DLR is s on the roadmap as this link:
For L3 Multicast routing applications, bridging to a Physical router configured as default gateway for the VMs, or Hardware Vteps with Ovsdb could be used:
It is also possible to enable Multicast Snooping on the dVS (similar to IGMP Snooping on Physical Switches), since the Vxlan based Port-Groups are provisioned on the dVS, dVS may handle the Multicast frames arriving to the ESX host, and distributing only to the VMs interested in receiving this specific multicast address through registering with IGMP.
These links could be helpful: