This some sort of new rule? Never heard this one before.
No need to rush into breeding.
If the female is ready she will produce, if she isn't she wont. Obviously the more mass she has the healthier the clutch will be and the bigger clutch as well, BUT and I stress this part, don't overfeed. Overfeeding can cause her to become fat and sluggish and more than likely she will not produce a viable clutch.
My male YB was breeding for me at 350g, so males it all depend on if they are producing sperm plugs, but like females they can go off feed while breeding so having them a little larger doesn't hurt either, but a fat male makes a lazy breeder.