You can do it in a similar way to the rest of the system, by using the actuators to disable the latches but it would mean atleast one actuator for each door, (may need 2 on a door depending on construction), cabling to each actuator and while you're at it you may as well central lock the tailgate as well so that would be atleast 4 actuators maybe 7 actuators plus cabling, plus a decent method of hiding all those cables (for neatness).
Putting an extra 4 actuators on the system shouldn't make too much load but as the BCM would never be expected to run that many there is always the possibility that it wont control all of them. Unless you buy genuine actuators (or figure out a way to manipulate after market ones) your extra door locks will not talk to the BCM and therefore wont relock with the system (when the locks are opened but no door is) and using any one of them alone will result in the car relocking itself after 60 seconds.
So in answer to your question yes it is possible but it may be alot of work for little gain. I have done the tailgate and it was relatively easy and does exactly what I want (stops arseholes opening the tailgate when the car is locked) but I'm still only one brick away from a theft.