My ClearNode http://www.node-ventures.com just added support for this (DMR Brandmeister only), so I know it’s doable. From taking a short glance at it, it looks like they added MMDVM_Bridge and Analog_Bridge.
A dummy node, 1999, was added to rpt.conf to facilitate the bridge:
If I understand correctly, you are trying to use MMDVM hardware for AllStar, it is possible if you are trying to use an actual MMDVM modem, NOT a hotspot board. There is a branch of MMDVMHost that can talk to AllStar via USRP. You would have MMDVMHost and AllStar installed. This could be on the same host or different hosts on the same LAN.
If you are trying to use analog hardware to operate AllStar, DMR, D-Star, NXDN, P25, then you can add DVSwitch Server to your AllStar node and access all modes from an analog radio (and Android, HTML)