We have a Multitech MT5634ZBA-USB-V92, and I want to know if this modem supports DTMF/DID for incoming fax routing?

The MT5634ZBA_USB modem will pass DTMF tones when in voice mode. It does not, however, support DID. We did manufacture a modem called the MT5634ZBA-DID that supported DID functions. You may find some available on the Internet for sale, but we do not sell them anymore.