The only way the lowest weight class will have very little forfeits is for it to be around the 140lb range. Teams will always struggle to fill the lowest weight, but at this point it time it is getting pretty ridiculous. When 1/3 of the teams do not field the weight, its time for careful evaluation and adjustment. Forfeits are not good for the sport and we need to find a happy median between letting the little guys have weight classes and at the same time try to have the least amount of forfeits.
If the lowest weight class is raised to 105-108 its not going to magically make the number of forfeits drop, but it will help. As someone stated earlier, at what point do you determine that there is an issue, 20%, 25% , 30%, 35% forfeits?