How accurate is the Sound Blaster support on the Cirrus Logic CS4237B chipset?

I'm not talking about the FM synthesis (OPL emulation) but the DSP part of the chip.

If I understand correctly, a Sound Blaster is basically FM + DSP so I'm wondering about using an Adlib (or OPL2LPT/OPL3LPT) + CS4237B to create a "perfect" Sound Blaster setup?