I wasn't commenting on using photon reaction - I was commenting on using this hypothetical reactionless drive (which would, presumably, produce more thrust then photon force - which the claimed device does from relatively small amounts of power).
If you had a reactionless drive, then the solar sail force would be negligible compared to the drive.
Even if the thrust from reactionless drive would be higher, it cannot be higher than the pressure produced by the photons on the solar cell, which you use to power the drive. If the developers claim that it does, then you have basically infinite energy.
If you had a reactionless drive, then the solar sail force would be negligible compared to the drive.