With a typical lightweight bird on a long, sea-level (or near) r/w, there's a significant excess performance available for TO. That's the reason for ATM/FLEX procedures, to reduce needless wear & tear by bringing the bird back towards a fixed thrust/mass ratio.
But there's little reason not to take advantage of full climb performance, even if that seams incongruous because climb N1 may be higher than TO N1. The engineers don't complain, because the reduced TO N1 serves as a warmup for the climb cycle. Only pilots seem to object to this apparent upset in the gages.
