With the ram expansion board you still only have an 68020 cpu running the show. The 8mb and the PCMCIA slot are mapped into the same memory space accessed by the 68020 cpu. I'd be amazed if you could get a switch to jumper only the 4 meg configuration without rebooting, nor that you can do this in software with the A1200 still booted up. I am 99% certain you will need to reboot whenever you alter the ram config from 8 to 4 meg either by hard switch or software, if such software existed. these problems don't happen with 68030 accelerator cards.
