Well, if you can manage it, the blast can be mostly linear.
I picture it like this: There's, say, a one degree angle between the trajectory of the ship and the trajectory of the fuel pallet. The explosion can happen arbitrarily far before their courses intersect. This means that the blast can be (arbitrarily far) * (sin 1 degree) away from the course of the rocket.
But that [Edit: the fuel pallet] transfers a small amount of sideways momentum to the rocket. To counter that, alternate fuel pallets from the left and the right.
I picture it like this: There's, say, a one degree angle between the trajectory of the ship and the trajectory of the fuel pallet. The explosion can happen arbitrarily far before their courses intersect. This means that the blast can be (arbitrarily far) * (sin 1 degree) away from the course of the rocket.
But that [Edit: the fuel pallet] transfers a small amount of sideways momentum to the rocket. To counter that, alternate fuel pallets from the left and the right.