General rule of thumb: ea E-string should be 1/8th" in from the edge of the fingerboard; But YMMV. If the there is binding along the edges of the fingeboard, that doesn't count. Measure from the fingerboard itself.
I think you should still measure from the outer edge of the binding. The binding is not extra width on the fingerboard; it's replacing part of the fingerboard. The frets still extend to the edge of the binding and the bevels begin at the edge of the binding.
To cure: re-fret job; or nut job to bring the strings closer together and away from the fingerboard edges. But tight string-spacing might interfere with playing.
Be careful adjusting the string spacing at the nut. This has a huge influence on the feel of a guitar. I would never implement "custom" string spacing; just try to return the guitar to its original condition. It was designed with proper string spacing and strings not falling off the fingerboard. The nut spacing is not at fault, unless the nut is actually cut wrong.
Trust me... having designed and built guitars... the string spacing is carefully planned and should not be tampered with, unless the nut slots are actually off.