Don't stop at length yet. Just push past it a bit more. 0.5cm, 0.75cm, 1cm. Doesn't matter. Just push past it. When you focus only on your girth, there's a transference effect. What you gain on girth tends to be transferred slightly from length. Once you cement everything, it will balance out. Same go for girth. Push the girth past 0.5cm to 1cm before cementing.