I've been wondering if it's possible to "progress" towards enlightenment if one has certain set of beliefs which may (or may not) be false (or illogical), but which do not generate conflict between expectations and experience. If we understand dukkha as the result of a dissonance between worldview and experience, one could a priori think that unfalsifiable theories may not generate such dissonances (and therefore, may not contribute to the perpetuation of the conditions of dukkha), because there's no experience that can disprove such notions.
For example, if one says that "our true self is formless, without comprehensible features", how could this view be a hindrance in the path? After all, that belief does not seem to necessarily contradicts the essence of anattā, because no khandha can be considered that alleged "true self", and so, non-attachment to khandhas may also be the path to attain that "true self".
Being more general: can someone attain Nibbana while still holding some false notions about self or reality?