Some notes if anyone in this thread is a bit stuck... or reading it and wondering if it's possible...

For a Bass VI using Fender .024 - .100s, all I had to do was:

1. ever so slightly widen the hole in the tremolo where the low E string went through
2. widen (and deepen) the nut slots -- I literally just used the strings themselves for this as they were all wound, so they worked as files

If I was to do it over again, I would probably plug and re-drill the holes for the machine heads for two reasons:

1. moving the low E tuner a bit further from the nut would mean only the slimmer part of the string would be wound around the post
2. moving the low E tuner a bit further from the edge of the headstock would mean I could fit a set of vintage style (kluson) slotted tuners

But even without doing that, it plays really well as a Bass VI. Stays in tune, isn't buzzy, etc.

You could also try with .084s like what come default on the Squier VI's, but I think you'd have the same issues as the Squier does with those (floppy E).