Indeed Terry 
Here’s my point: Yes, indeed, follow the maker’s recommendations, by all means.
That said…
I can see where Rod’s coming from, if you’re selling to a player who typically plays for multiple hours per day, but in general, the idea that a “New” flute which is coming directly from the maker, should need to be played in slowly, doesn’t make a whole lot of sense to me.
When you buy a newly made flute, what did it go through (or what should it have gone through) in the process of being made? Would it have been oiled during the process? Would it have been oiled within a few days of shipment? Wouldn’t the instrument need to be played for more than 15 minutes at a time in order to be properly tuned and voiced?
Where I worked, each instrument was played for several hours during the tuning and voicing process, more than enough to show any problems that might arise in the normal course of daily playing. With 350 or so instruments made from Boxwood, Grenadilla, Rosewood, Tulipwood, Kingwood, and a few other odds and ends, I never saw a single instrument crack during this process, nor were any returned by customers for cracks related to “overplaying”.
Again, just to be clear, I absolutely think it is imperative to follow a maker’s break-in instructions, if only to CYA with regards to the warranty, however I’m at a loss to understand how a newly and properly made flute would/could crack from a half hour to a hour of play per day to start - particularly because the instrument should have gone through more playing than that while being tuned and voiced in the shop.
I’d absolutely agree that there is a very real danger of cracking a flute that has been sitting, unhumidified, and unoiled for a long period of time, but these circumstances shouldn’t apply to new instruments.
Loren