Hi Flip!
Here are some thoughts:
Jeff's Dire Wolf is a 32 5 string, and he says it sounds great.
You might want to ask if Alembic can cut the top half of a nut for your string guages so you can switch it back and forth easily.
A B string, even a 130, usually has less tension on it than the other strings, so unless your neck wants to flatten out some it shouldn't be a problem.
For a BEAD bass, I would prefer a 35 or 36 inch scale, because one thing that you will probably notice is that it will be tough to get the intonation right all the way up and down the neck. When you're using the BEAD tuning, you will probably be playing on the B string even more than you would on a 5, and higher on the neck, too. It may become frustrating hearing the slight tuning imperfections so often.
Just some thoughts...
Take care,
Charles