It's nothing to do with age. It's all in the processing.
I disagree. Not the age of the wood mind you, but the age of the
tree it came from. There is no (practical) supply of true, old-growth maple in the US. (now most of it comes from Canada) What little there is, is predominantly in our tiny national parks. I believe the age of the harvested wood helps, in that the wood will be VERY stable through-n-through. I had often thought old OLD
OLD cues would make exceptional shaft wood- great for those that have no veneers in the splice or just are beat up in general. Curt right above the splice, that can be turned to a clean 30" blank easily.
Old wood was quarter sawn & traditional kiln or air dried, hence the yellow. It was also big trees with heart wood.
For the sake of a shaft, 1/4 or flat sawn makes not practical difference. Select your flat sawn 1+" wide boards carefully, rip them into 1" squares, and turn 90 degrees and you have a 1/4 sawn blank. It's truly magical. It is true that flat sawing is done for greater yield from a log; however with so few good logs, you cannot expect a modern mill to waste literally tons of perfectly good wood to get a few 1/4 sawn pieces(but some do, and you pay for it). Select them by hand, and know what to look for.
I also agree drying ANY wood too quickly is not good. Vacuum kiln or plain old air kiln drying is OK if dome properly, with CARE for the wood, and not so much for production. I definitely prefer air-dried (such as OLD cues were) but it is nearly impossible to find. When we hang our shaft blanks and other cue assemblies and parts, we are essentially air-drying them. Take a cut, age it. Take a cut, age it. It takes forever to make a cue, but if you age it carefully, it will last forever...
When I made guitars, I used 1/4 sawn planks for the neck blanks. Then I learned I can use less expensive flat sawn beams ripped and turned on edge. I then discovered laminated necks were even more stable stable. So, I began laminating them with Walnut, and buying less expensive boards rather than beams. I have ended up with the most stable neck out there. I just dug out some blanks that have been neglected for 5-7 years and they are still as straight as the day I made them.
Nowadays only the sapwood is used, often times flat sawn for high yields instead of quality yields, and it's then vacuum dried. So it's not the age that changed the wood but more how we have changed how we process & choose wood.
Both sap and heart wood is used (unless you meant for shafts specifically)- again, a mil won't throw away all that lumber! I got a lot of my wood from a mill that did predominantly wood flooring. (you would not believe what some people walk on) and I had my pick of the litter- the curly, bird's eye and burled/crotched wood was not wanted for flooring, because it stood out too much among the other cleaner boards. Their loss was my gain! But to the point- the entire log would come into his mill, and be processed in-house. He had his own kiln (not vacuum) and dried them himself. I liked getting wood from him because it was always quality stuff- sap and heart wood. He loved the wood- and quality was never an issue because of it.
Back to the age thing, the older growth wood tends to have a higher count of growth rings, which many cue makers want in a shaft. I think it is a good idea as well, because it reduces the amount of run-off in the taper. Color is less important to me, but I agree nearly everyone wants snow-white shafts with no 'character' in it. Because of this, many makers are bleaching their shafts as well, and I REALLY disagree with this practice...
Who started the whole "Whiter is better" thing anyway???
I have no idea, and perhaps they don't either. But, the point is, particularly in cue making, I don't think ANYTHING is too goofy...