Is that the highest the neck pickup will go? You probably don't have a lot more
height before it starts to get in the way of the strings, but even 2mm is worth it for some extra output, as Tele neck pickups aren't known for their grunt. If the springs are maxed out, then you could try some fairly hard foam under the pickups. Or even stick a bit of wood/ply at the bottom of the rout to raise everything up a bit, which also works if the adjustment screws are about to loose their grip.