Whilst I realize it is not popular ; I consider it is useful to distinguish between science and philosophy.
Where philosophy is itself divisible as
- values and ideology
-epistemology: what we know and how we know it
-ontology:essential nature of things and definition of the meaning of words.
Personally I also find it useful to restrict the meaning of metaphysics to ;
- relations and correlations between subjective experience and the objective material world and
the meaning of of mysticism to - profounder aspects of subjective experience.
I include these two later words just because some physicists seem to conflate the two as meaning
"just some obscure, irrelevant and speculative matter."
Whilst the vast majority of interpretations of QM (Copenhagen etc) are 'ontic' (eg electron location is actually fuzzy);
there have been 'epistemic' interpretations (eg electron location is fuzzy knowledge), which don't rely on hidden variables.
Eddington's 'Fundamental Theory' seems to be an example of the later.
Whilst this was never successful; an epistemic interpretation of the collapse of the wave function following observation does;
have appeal to me as the " the response of quantified uncertainty to a new observation"
Finally I mention all the above as context to my comment that whilst most of the discussion has been in the grey area between epistemology and theoretical QM; BUT when we start to enquire about 'reality' as distinct from say the shared quality of objective material phenomena; we are likely to encounter deeply held metaphysical differences !
