[ambulancechaser]

have done this lots of times.

    (if (test) (then) (else))
    (if true #_(test) (then) (else))
    (if false #_(test) (then) (else))

makes it quite simple to leave the tests in. Also, quite easy to raise forms (structurally raise) and reevaluate the form and then undo but not reevaluate the form to have it modified.