I feel your pain.. I have a 93 Corvette Proline & a 95 Thumb NT, both 5 string
The Corvette bridge will fit virtually any B string yet the Thumb needs a tapered B to fit comfortably?
When I used to have a string endorsement with Bass centre Elites, I used to order separate tapered low B’s in a .130?
so my suggestion would be to contact the Bass centre?
I haven’t used Elites for a few years since I received some rusty/corroded sets, but I presume they’ve improved in time?
When I restring the Thumb bass these days, I tend to use D’addario Pro-steels that have a tapered B..