"Don't understand why TC, thought that this would be a good compromise on a Flinter."
Because the 1-48" twist will shoot both roundballs and conicals passably well. A 1-66 twist for roundballs won't shoot worth a damn with conicals, and a 1-24" twist for conicals will do some amusing things with roundballs.
The 1-48" twist gave everyone the ability to choose what they either wanted to shoot, or what they were required to shoot.
Then, of course, Pennsylvania changed the game by making primitive season roundball only, and that's when we got the Pennsylvania Hunter flintlock with the 1-66 twist barrel.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.