Tool Sets > Hanging Position Tool
From the "Position Symbol" pull down, find the same symbol in your document that you are using for the motor in question. Place it in the same location as the motor in question. (And remove the actual motor)
Then using the Insert Load Tool, add the motor / pickup weight to the exact point where that motor would have been, this gives Braceworks the weight that would be applied to that spot on the truss.
Onto your Line Array weight, using the Insert Load Tool, add the weight of the line array to the contact point on the truss. (You will have to do the calculations yourself as to how much weight is on the line array point, and your pullback point.)
If you have used the Speaker Array Tool, make sure to turn off "Include in Calculations" on the bumper and speakers.
I use the hanging position tool because it easily duplicates the motor symbol in question. You could modify any symbol really and make it appear to be the same as the motor.
What this is doing is removing the actual motor, there is no longer a motor there. On your 2D plan, the Hanging Position Tool will have the icon there so you will still see that a motor exists there, in your 3D, you will see the motor, but the chain will be short. Braceworks will not think there is a motor there, but will still calculate the weight of that motor and PA.
Cheers,
Enoch