Alright maybe i was being a little drastic,
It does not completely change it,
But let's use my box for example.
If i didnt use 45s,
It wouldn't have the correct back-wave profile from what I designed, thus won't do as I designed it to, losing output, and adding vent length, meaning that the Front Wave, from the woofers, and the backwave from the vent, won't be as I modeled it, and that was optimal.