HA2NON
DMR uses AMBE2 voice encoding, P25 uses IMBE. Transcoding between them would require audio transcoding hardware, which only the openSPOT3 has. Note that DVSI Inc. does not sell IMBE capable audio transcoding hardware anymore (IMBE is a very old audio codec), so even the openSPOT3 can't transcode P25 DMR.
What you can is to use C4FM/Fusion radios in VW mode and P25 transceivers. The openSPOT2 supports cross mode operation between them, as Fusion VW mode also uses the same IMBE codec as P25.