"Initial travel" and "initial advance" is a incorrect description. "Initial timing" is where the timing is before the distributor centrifugal (mechanical) advance starts. There is no such thing as "initial advance" or "initial travel". "Timing advance" starts between 700 and 1200 RPM, depending how it is built into the distributor. Aftermarket performance distributors are designed to have the "timing advance" start at a higher RPM for use with high performance camshafts that must idle at a higher RPM due to longer valve duration and increased valve overlap and low vacuum. .
GM did the same thing to their so-called "stock" distributors.
A "stock" Pontiac Ram Air IV distributor centrifugal advance mechanism and the mechanical advance on a "stock" Chevrolet K66 transistor ignition starts at 1100 RPM.