I don't understand all you saying don't rev it to much after the rebuilt "bollax", hit the limiter if it's built properly it will be fine, every single engine iv rebuilt iv let it warm ur at a high idle, then given it a good rev, Iain I love your way of running it in, sounds like a true machanic, none of this fannying about, "oh I have to run it in to bed in the pistons" lol.
Top work mate, hope all goes well once it's remapped.
Daniel
run it in, the same way it will live it's life