I've got a 4-string BTB400 series and am thinking about stringing it BEAD. The 35-inch scale makes me think I can pull it off, but I'm a little concerned about the thin (front to back) neck being able to hold up to the extra tension. I'm also wondering if the bridge saddles will accommodate strings that much thicker than they were designed for. Thoughts or experiences on the topic are welcome. Thanks!
I wouldn't worry about string tension. In theory you should have less tension as the "b" string is typically the lowest tension in the set. The "d" and "g" strings are typically the highest tension.
It will have less tension, and should work fine. You will have to file the slots in the nut to allow for the larger diameter strings, and perform a new setup; i.e. relief/action/intonation.