That's the part of the preparation where you gather up aspects to get enough shifts to cover the complexity of the spell.
It's a bit like a gps navigation system. If you want to find your way around in your state, that's not going to be a problem, that's what it's there for by default. If you want to go further, you are going to need to get the right maps, load them onto the device, etc. In either case though, you are going to have to program the address, or you won't get anywhere.
The same, I think, applies to thaumaturgic rituals. Easy rituals don't require much prep, but you still need to spend some time on it. You need the symbolic link (the address), and you have to draw up a circle to be able to power the spell (programming the address into eh device).
Thaumaturgy is not really meant to be cast in a conflict situation, unless all the preparation steps have been done (like the ward example). If you are able to get the symbolic link from a target (like pulling out some hair), that conflict should probably be over, and you can cast your spell in private. Or you can use the link directly in an evocation directed at the target, that would probably be the better option in that moment.