Quetiapine, especially at low doses for insomnia, is extremely unlikely to cause any form of EPS including TD. The information RE: this side effect is mostly because it is associated with the class of drug (antipsychotic). It is much more likely to cause metabolic derangements including weight gain, diabetes, high cholesterol, which would be the side effects I would be concerned about. The primary mechanism for which it is sedating at low doses have to do with antihistamine effect. I would discuss with your doctor a trial of an antihistamine first, if you haven't already done so. There may be other reasons he/she would want you to take quetiapine other than insomnia, so keep that in mind before making any change.