Psychometric tests are not more valid or more reliable than other psychometric tests - rather a test is valid or invalid and reliable or unreliable in itself.
However to administer a valid and reliable psychometric test to oneself, means the data are contaminated from the very beginning.
And if you want your personality or intelligence quotient or any other aspect of your psyche measured, you need to pay a qualified, professional psychometrician.
In fact you need to pay not one but two independent psychometricians to make sure the result is the same in each case.
However if a Movement encourages you to administer to yourself a test that is invalid and unreliable for free, you know that Movement is a cult.
For instance cults like Scientology offer free bogus personality tests to appeal to the narcissistic.
And cults have their own internal dynamic. They appeal to the felt needs of their members, such as belonging. Cults are impervious to evidence. Oddly enough cults often attract the best and brightest. And cults regard curiosity and dissent as, at first, bad manners then secondly as disloyal and finally as treacherous.
At the deepest level, cults are paranoid. And paranoia, you remember, is psychological preparation to attack.
So caveat emptor.