I didn't realize the idea of fat clogging a hole was not commonly accepted. Never seen it myself, but never had one go that far. Maybe regional.

It is surely believed by bear hunters. Some deer hunters too.

As for less blood with modern bullets, only if it doesn't exit. Modern bullets do expand better. I have had partion and interlocks not exit, but I think it the shot placement, not the bullet. They expanded nice though.