and why some can take more powder and still show no signs of pressure and still be entirely safe.
Careful about that part right there... JB has said numerous times that it may not show the typical signs, but that doesn't mean it's safe. (Which is the point I've been making for a while on this thread)
I think Bob summed it up well. I just hate to see people misinterpret the information when it hasn't been fully presented to suggest that it's safe to run loads that are very likely exceeding 65K without understanding the consequences.
Read about Layne Simpson's 7STW loads sometime. Perfectly fine with regard to all the "usual" indicators and running well over 70K pressures when finally tested.
