When boosting the accuracy of a corvette or PD module, the boost lasts for ONLY that attack. e.g. if your PD has accuracy = 2 you can spend 1 targetting token to attack with 2 accuracy or 2 tokens to attack with 3 accuracy. The next time you use the PD, the same applies; spend 1 token for 2 accuracy or 2 tokens for 3.