Traditionally, Mame doesn't take advantage of anything at all.. It's mainly for documenting the hardware and perfect emulation. That games run at all is, according to the devs, a side effect.. For example, Mame doesn't use any 3D effects from a PC's graphics card for 3D arcade games like Tekken. (having said that, it does use D3D, but for effects and overlays -- just drawing the frame itself) About the only thing that helps Mame run faster is raw CPU power.
For something like CPS games, I think what's really wanted here is for someone to take the CPS driver from Mame, and write an emulator for the Amiga using it as reference, as opposed to optimizing Mame for the Amiga. Perhaps in that way, use could be made of the 68000 and graphics capabilities. Zinc and Modeler, for the PC, use 3D routines in this way to emulate 3D arcade games. (I'm not saying an Amiga optimized Mame wouldn't run faster than whatever port there is for it now, but I doubt it would help much, or at least, not nearly as much as an entirely new emulator written for the Amiga)