Depending on which armor make, screen use had 1 large tab and 41/2 to 5 small tabs. Some makes won't allow this as the chest ridge can be higher.
You can also trim off the large rear tab if they cover correctly and have enough length.
As seen in the photos below, there are no large tabs on the rear of the shoulder bridges. This is not specifically mentioned in the CRL, but removing them is highly recommended if possible.
It is advisable to glue the front of the straps when you have the rear backplate in situ so they sit correctly, I use a small tall box between the chest and back so all is in alignment.
Clamps, magnets and tape can be handy to have around