I would assume as Rat...par baked if not cooked out.
....Not a pastry chef but I can't imagine what's in the filling that actually requires much ovening...cornstarch-based, lemon curd (I gather from Cakeface) or creme pat styles are stove-top deals...at least they will work that way with a cooked out shell hot or cold...(interesting Bazza). The mixes are usually stabilised so even eggs wont require as much time/temp as the base.
I push the blind/par baking thing beyond the recipe recommendation 'cos I find chefs, not being pastry specialists routinely undercook short pastry with the result not being 'short'. I find 'water-proofing' with eggwhites to be a sensible practise for the same reason. Imho, If there is a 'magic bullet in the kitchen its eggwhites...the things I do with them! I'm wondering if 'white-washing' the greased tin prior to lining might add a layer of protection for chiller life...hmmnn?
What I'm getting at is perhaps the recipe is trying to 'multi-task' the two cooks without stressing it so that if the balance is out on the day it will be to undercooked pastry, which when corrected, which would logically lead to an overcooked filling causing the shrinkage through evapouration...when stuff dries out it gets smaller.
I just wanted to put this out there 'cos one of my chefs is having a diiferent issue with his chosen recipe for the same tart and when I look at it it doesn't make sense to me on the 'combo' ovening level....my instincts trust technique over a given recipe.
Just trying to help and certainly don't want a serve as have been handed out lately...