Default [Q] Riff Box + Downgrade of SPH-L720

Riff Box owners:
Have any of you had luck restoring a dump .bin file of tz, rpm, mdm, sbl1, sbl2, sbl3 and aboot backwards to a pre MJA dump (e.g. MDC) from MJA or MK2 using the riff box and the jtag pins next to the left side ribbon?