Henry Spencer wrote:

The other is that your goal is not to optimize the instantaneous rate of
energy addition, which is F dot v , but to optimize the total energy
added, which is integral(F dot v dt) . And because the problem is
nonlinear, these two strategies are *not* equivalent for low-thrust orbit
maneuvering: energy added yesterday changes the orbit and thus changes
v today, so it can be better to accept a lower rate of energy addition
yesterday if it will give better conditions today.

I might add that the topic of optimizing low-thrust orbitla transfers
is one of the hottest topics (well, the only hot topic) in the orbit
planning business these days. The solutions and strategies are very
closely guarded industrial secrets.

Brett