I always thought they should be done hot?The spec from land rover is 360 from cold. 400 is high but you are really looking for no more than a ten percent imbalance between all four.
Do the compression again stone cold as the metal expands when hot and can hide things. It's just for peace of mind really.
Your smoke could well be injectors, I'm having the same problem with mine after a run away
It could also be that someone has fiddled with the injection pump and boost pin. The trouble I find is once something has fiddled there is no way of knowing or how to put it back to stock original.
Since I've owned the car I've done the timing belt but never fiddled with the pump or fitted boost pin/ring. I guess there must be a way of setting it all back to default. Maybe worth looking into before I fit a new belt.