ASDF probably doesn't go deep enough into the implementation for some of these variants to make a difference, but might as well include them anyway. Here's a patch for that.
Allegro now has (potentially) 16 variants for each OS platform:
ANSI/modern 8-bit-character/16-bit-character 32-bit/64-bit SMP/non-SMP
(expt 2 4) --> 16.