> Standardized Field Sobriety Tests were created to test for alcohol impairment and NOT marijuana impairment. The current Field sobriety tests are unreliable when it comes to an indication of marijuana impairment

The only "field sobriety test" that has any scientific basis is a properly administered horizontal gaze nystagmus test, and even that is easily rendered completely inaccurate by things like holding the object too close or too far from someone's face, moving the object too fast, incorrect angle, not viewing the eyes at eye level, movement of the fluid in the inner ear, dry eyes, caffeine, contact lenses, stress, smoking, seizure medication and antidepressants.

So that one is garbage too. Field Sobriety Tests (the dog-and-pony show) exist for no other reason than that they will almost certainly be used to claim probable cause to force an arrest and chemical testing.