What is the most effective method to prevent a soggy shortcrust quiche base?
In my personal experience, the freezing method has never worked well. I have a traditional quiche pan - white porcelain with vertical fluted walls - and it gets very cold in the freezer. No matter how I have played with temperature and top/bottom heater setting afterwards, I have never been able to compensate for the effect of the cold porcelain (a bit like the opposite of a preheated pizza stone) - I always got an underbaked soggy crust bottom with crispy to overbaked crust walls, and a gradient in the filling's baking. 

I can imagine that the freezing method might work for people using American pie tins or similar, but it has a serious disadvantage with a porcelain pan.