I also have had an TRA1200 board with 8MB RAM and it was also PCMCIA friendly.
It could do everything with the PCMCIA port. However... this was only the case
with the following combination:
Kickstart ROMs 3.0 + WorkBench 3.1 -> PCMCIA WORKING!
Kickstart ROMs 3.1 + WorkBench 3.1 -> PCMCIA NOT WORKING (only with 4MB SIMM).
So I'm curious what ROMs you're using?