Do it! I bought a used Tribute Kiloton to do something similar, only I was going to (maybe) put an MFD single coil from the SB-2 in it. I was talked out of that (about 90%) and thought about a Dimarzio Relentless jazz pickup instead. I was going to just use a stacked set of pots for the volumes and leave the 3-way pickup switch for the humbucker. It was all worked out perfectly in my head, then the bass arrived and it's so beautiful I hate to start cutting on it. Please keep us posted.
I've been back and forth so many times!
I think I'm gonna do it.
I talked to Fralin himself and he thinks the 10% will match the MFD just fine, and gave me the specs for proper neck pickup position, which I'll send to my local guy here in Atlanta.