When Apollo astronauts departed the lunar surface in the Lunar Module's Ascent Stage, it appeared to rise vertically ($\beta$ = 0) for ~10 seconds and then begin the "tipover" (videos of Apollo 15, 16 and 17), the program of increasing $\beta$ ( = $\pi/2 - \gamma$) with time, transitioning from vertical flight to orbit, where $\beta$ was just short of $\pi/2$ at ASP shutdown.

In the videos, especially the out-the-window video, it is apparent that the $\beta$ vs. time program is not a smooth pitch-over but instead has discrete (short) intervals of incresing $\beta$ with intervals of nearly-constant $\beta$ between.

QUESTION: Given the physical and performance parameters of a fully loaded Ascent Stage, what would be the optimal time profile of $\beta$ to minimize propellant use attaining the initial (18 x 87 km) lunar orbit?