Iron Eagle - Heck, just finish with flat tips, fly her while you're fabbing the composite tips, remove the flat tip covering, install-n-cover the new tips. And go flying again. Hey - the best of all worlds. Oh, just don't whack the ground before ya get the new tips finished.
Just messin'. Do you have any pics of a mock up? Just curious as to what the proposed end state of the tip will look like. Because I'm so new to the hobby alternative wings tips are very "foreign" to me and I'd like to see your creative alternative.