In the presence trigger's condition put
this && (damage radar1 < 0.9)
"this" there means the proper condition of the trigger as it is configured (BLUEFOR present), after that you may add as many other conditions as needed. If the BMP WP previous to Seek and Destroy is a MOVE one, you dont need, in fact, you dont want a SWITCH trigger, just sync the trigger with the MOVE WP so that the MOVE will be accomplished when the BMP reaches it AND the condition of the trigger is met.