2 questions about the cinnamon chocolate tart with pecan crust: a) How do you feel about a walnut crust? and b) How far in advance can I make this?
A walnut crust should be a fine substitution.
In all of my decades of eating and making pies/tarts/etc., I have *never* had a single one that was better on a subsequent day than the day it was made.
Many pies are enjoyable for a couple of days, but the first day the crust is in the best condition because it hasn't started to absorb moisture (from the air, the filling, etc.).
uses a cold filling and a blind-baked crust, so one would expect to be able to make the filling and dough the day before. I'd blind bake the crust the day of, then fill the pie not too long before serving.
Again, this is a judgment call based on your tastebuds. If you enjoy boxed pies from your supermarket or have previously made pies before and found them acceptable to serve to others on subsequent days, you can proceed with caution.
In the end, it comes down to the same judgment call you have to make for anything you set in front of a diner, whether it's yourself or someone else. Is a slice of day-old pie good enough? Your call. Is it going to be as good as the day it was made? Not in my experience.
There are tons of things to make in advance, and some things that really need to be made in a timely fashion.
In my house, there is no way I'd assemble pie on an advance day but you don't live in my house.
If you do intend to serve this to guests, a wise and cautious cook would do a test first.
Personally, I think nut crusts like that hold up better than pastry crusts. That has been my experience.