For the record, checkerboarding DOES NOT DISTURB the broodnest. Alternating honey and empty comb is done above the broodnest very early in the season - normally before the cluster has expanded to fill the starting brood chamber.
I resist all broodnest disturbances, except one: I sometimes take a frame of brood from a stronger unit to support a weaker colony. In that case, the broodnest is closed up on the donor unit, without replacing the pilfered frame.
The bees maintain a "safety margin" in all survival requirements. If left to do it their way, they don't get caught short by a sudden, and severe cold snap. To account for those extreme conditions, their safety margins are quite conserative - wider than needed for normal conditions. So, under normal conditions, they can handle manipulations that encroach on their broodnest temp control safety margin. But I'm inclined leave them the whole range of their proven limits.
In addition, its difficult to judge colony strength on a hive-opening day in the early season. More than half the bees may be in the field foraging. Have seen cases where the whole cluster was in the field except for a single layer of bees over open brood. But then, I'm in hives earlier than most.
There is another (subjective) reason we don't scramble the broodnest. I feel that disturbance creates a time delay in development. The colony is slowed for the time of reacting to the change, and I don't want to slow growth by any means.