Having read a few articles on the suggested new uses for the crippled Kepler space observatory with only two out of four functioning reaction wheels, several ideas suggest that Kepler’s pointing problems would be minimized, if it aimed its camera within the ecliptic plane.
One of the ideas advocating Kepler's use for the target objects within the ecliptic is this proposal for A Survey of the Ecliptic Plane For Transiting Planets and Star Formation (PDF), that mentions:
This White Paper calls for the use of Kepler to conduct a survey in the ecliptic plane to search for planet transits around stars at high galactic latitudes and to study star forming regions to investigate physics of very young stars not studied by Kepler in its prime mission. Recent analysis by the Kepler project indicates that the spacecraft's best pointing will be possible in the ecliptic plane.
The proposal seems otherwise sound enough. Searching for planet transits was within the Kepler's tasks anyway, with its original goal to determine the frequency of Earth-like planets around Sun-like stars and its wide-angle view, albeit monitoring them for years, instead of what would now be possible perhaps for weeks.
But I couldn't find any other reference as to why Kepler would be easier to control when pointing towards targets within the ecliptic plane. This seems to me rather non intuitive. What are the reasons behind this claim? Have any tests been performed on the current Kepler's attitude control capabilities that would officially support this theory?