I ran across the little jumper mod to connect pin 2 to pin 10 on the floppy header (in this case, an A2000, but would work for any DF0:), with the net result being that Amiga thinks there's no floppy in the drive.
I have not tried it yet on the boot swap adapter I have, but, on an A500 (or 1000, or A2000 jumpered for a single internal floppy) if one could do this jumper in addition to the SEL line X, would it render the internal drive (missing the extra circuitry, and therefore not functional) as just a drive without a disk?
(If it worked, a TPDT switch (3 poles, 2 positions) would be needed, or a second switch of SPST type to effect the jumpering.)
