I don't think adding debug/safety 0 are really worth it. In this:

    (declaim (optimize speed)
             (ftype (function (fixnum) fixnum) fib))

    (defun fib (n)
      (if (<= n 1)
        1
        (+ (fib (- n 1))
           (fib (- n 2)))))

    (print (fib 46))

adding `(safety 0) (debug 0)` took the time from 13.17s (with just the `speed` declaration) down to 12.94s for me. Is a 2% speed increase really worth the danger of `(safety 0)`?