The 3032 was initially designed for the 518 and 218 series of Roboscans and the Martin serial protocol, but it sends RS485 just like DMX512 does, so third party software should be able (and is) to send DMX through the card instead of Martin protocol.
I've had a look around the card and the data sheet from the manufacturer and it should not be difficult to implement. It's a simple 16550 UART which connects straight to the ISA bus, and can be configured as a regular serial port (by setting I/O to 3F8 and IRQ to 4, and the like), but when operating as a 3032 Martin used some different addressing. Nothing that should be impossible to get around.
The 16550 UART should be able to transmit and receive DMX as it has its own 18MHz clock on the board and the control registers are readily available (and documented). The PC serial ports are unable to because they are clocked from the ISA bus, and therefore limited to lower data rates because of the lower clock speed.
I would be happy to write a driver for this card, as there seem to be quite a few of these old boards floating around. I have extensive experience with C++ programming, but need some API documentation to write a driver for FreeStyler.