atlas symbolik switch case

i'm sure there's a better way.  but how?  symboliks needs to have an xref for it to apply the constraint.  perhaps i should just check for the register and get that from the SymbolikEmulator.  i knew this was a hack, but wanted your input before i solidified on a way around it.
i'll stew on this section.  i wrote it 8 months ago.  perhaps a fresh eye will show unnecessary logic.  please let me know any thoughts you have about how you would approach the xref hack.