No, it doesn't. It searches the machine for what is available (IDE or PCMCIA) and the first thing with a boot record, it boots it.

If the PCMCIA is not there and the hard drive is dead, bad boot records, or not on the IDE BUS, it puts up the flashing "?" inside the floppy disk. While the "?" is flashing, when you put in the PCMCIA, it takes a second to find it, and then it boots.

I think it has something to do with that separate CPU in the 5X0 series PCMCIA, and it needing the PRAM for the PB to see it.