No - I don't think Haml will ever do any optimizations that will actually change the rendering of a document. Consider for example
#foo
%p bar
baz
If we removed </p>, this would render as
<div id="foo">
<p>bar
baz
</div>
which is equivalent to
<div id="foo">
<p>bar
baz</p>
</div>
and
not equivalent to
<div id="foo">
<p>bar</p>
baz
</div>
Unless you can come up with a way of removing the tags that is guaranteed never to produce this sort of change, it's not safe to include it.