I'd definitely encourage playing around. But, keep in mind that reflexing or adding static tips to a bow will change it. Tell us more about the design and we can help. In general, when I tweak a bow I only reflex the tips a bit. If I am adding static tips or reflexing a lot, I like to totally rethink the design. If the bow is long, I will often cut it down. Long bows don't like static tips as much as short ones. There is a lot of mass in the tips. Adding sinew is also a great way to make a so-so bow a great, short static recurve.
Have fun,
John