I dunno if a bow shot in the unlimited class needs to be tested for draw weight prior to shooting in competion, or even if a 51 lb bow could be competive in that class, but the possibility of shooting a previously undrawn bow is intriguing.
About 10 years ago I built a bow and only tillered it out to about 23" and then projected the draw weight out to 28". So, it's not 100" accurate but very close. When I tested the bow I rapidly took it right to 28" and got phenomenal speed. ( It was a very extreme recurve design. The first shot was the fastest at 215 fps and it went steady down with each shot until it got down to 157 fps and lost about 18#. It settled in at about 178 fps with 10 grains per pound.