For Amiga long ago should build 030/040/060/PPC processor card with DSP and 16-bit audio codec with mixer Paula and Line output and input and microphone/headphones/CD-input/Digital etc.
Cards on the clock port / Zorro is nothing special, inefficient.
Falcon DSP bus was quite slow too, slower than ZorroII. I guess that more DSP software could be ported to Delfina.
Falcon had nice 16bit screenmodes although it lacked sprites and its blitter was more primitive than Amiga's one.
Anyway skilled programmers use DSP to accelerate drawing lots of software sprites:
https://www.youtube.com/watch?v=87EMhNkTkeothey also have a nice NeoGeo emu, btw.