They usually do. Although the revelations are often basic, repetition of known ideas, or just another perspective on existing knowledge. Creative solutions, new ideas, and insightful combinations of knowledge are the minority. Outright bizarre and misleading stuff and delusions are the smallest fraction.

Of course thoughts experienced while in an altered state should be evaluated again while sober.

For mystical and spiritual experiences, not everything needs to make logical sense or be consistent. Something Ineffable will always remain. In mathematics there are also limits, singularities, infinities, and so on.