Does the MultiAccess Server support raw mode TCP, like the CommPlete?

Yes. This is now a Modem Usage option when the usage is set to Modem Sharing.
Raw Mode = Yes sets the TCP port to a RAW socket. User data is treated as is and the Telnet Command Escape capability is disabled.
Raw Mode = No allows the Telnet command parser to look for escape sequences that are used to communicate control functions. A common example is to support RFC-2217 Com Port Control.
This was changed in MultiAccess software (version 1.12). Please see Resolution 3376 for instructions on updating your MultiAccess MA30120.