From the research description it should allow any colonist to become a redcoat immediately but it only sets the militaryTrainingTechModifier to zero. This leads for all military trainings to exit the training job immediately. But since the training jobs accumulate for each animation cycle the necessary training points until they reach EntityDB.HumanStats.militaryTrainingPointsToRedcoat div overseer skill or the training animation ends this seems to counter the wanted effect completely. Either set EntityDB.HumanStats.militaryTrainingPointsToRedcoat to zero if the research goal is reached (workaround since it requires the newly conscripted colonists to run through one training cycle) or better check achievement when adding colonist to a barracks workforce or making an overseer military.