I guess it might be interesting to see how quick the CD system DMA will do the copy so here is the code to DMA copy buffer for TOP/FRONT loader (not sure the size value is correct so double check that). I fully expect this to be slower. Remember the 68k is in a halt state while DMA is active. I'm not even sure you can DMA into palette RAM but it would be interesting to see what happens non the less, it might for example stop the snow effect.

	lea	$ff0000,a0
	move.b	#$00,$61(a0)
	lea     $7e(a0),a1
	move.l	#$FE6DFCF5,(a1)+
	move.l	#$82BFF693,(a1)+
	move.l	#$BF2902FD,(a1)+
	move.l	#$FFFFF97D,(a1)+
	move.w	#$FCF5,(a1)
	move.l	#CHUNKY_BUFFER,$64(a0)		; source
	move.l	#PALETTES+16*2*5+2+32,$68(a0)	; destination
	move.l	#$1F20/2,$70(a0)		; size (words)
	move.b	#$40,$61(a0)			; enable DMA