Its not the stack up of tolerances trust me with this one, there is more than enough adjustment for suspension angles. If you stack up all the tolerances were talking a couple hundredths of an inch, not 1/2 or 1/4"
This shop must not have the correct tool or knowledge to adjust the trailing arm plates to adjust the rear toe. Also, make sure they selected the correct vehicle. There is a huge difference in rear specs for sports package vs non. As a Ci you should have a sport suspension standard.