40% slowdown with dynamic /bin/sh

[Colin Percival]

<Newbie developer question>
   Would it be possible to ship a static /bin/sh and a dynamic 
/bin/dynamic-sh, with /bin/sh execing /bin/dynamic-sh if it is invoked 
interactively?  If I'm understanding the issues correctly, a dynamic 
/bin/sh is desired for the benefit of interactive users, while the 
performance of a static /bin/sh is only an issue in non-interactive cases.
</Newbie developer question>

Colin Percival