Indeed. For neatness I'd like to have a board piggybacked on Gayle with all the typically used connections easily accessible on pins, but I've also soldered wires directly to chip pins on my on A1200 so I can't lecture
I haven't calculated the speed myself,, but the complete Spare_CS cycle is 7 or 8 clocks long IIRC, so reducing that by 3 will give you a not-quite doubling of potential speed. Maybe 1.8MB/s if we take 1MB/s as the Spare_CS theoretical maximum, at a vague estimate.