Sure - but I did appreciate the links you provided and enjoyed reading them as I understand the topic of quantum mechanics and the debate surrounding the existence of the particles and fields etc., much more thoroughly now.
I would only add that it doesn’t matter whether I think something actually exists… I’m not so interested in whether something actually exists “for me”. There is no existence for me or for you etc, it’s just existence.
This may be a rare case where we say the same thing but language gets in the way. But to me to talk about ontology and epistemology etc is to miss the mark and to muddy the simplicity of the matter and to diverge to the realm of philosophy, whereas the realm I’m interested in is the experiential one, and what can be put together from experience. We can argue or debate philosophy but we can’t argue or debate experiential matters 
To add to it, when you say:
Again, its actual existence or not has to do with labels, definitions, conceptualizations and ontological positions about existence itself (you tacitly assume a definition and ontological position about it every time you use the word -even if you are not aware of which-).
What I’m getting at is I don’t think this is true even for whether I think something actually exists. To reason or conceptualize existence (as in whether something exists, or the nature of existence) is to be missing the point that it’s an experiential matter, not a cognitive one. There is no definition or ontological position to be had, either - it’s again an experiential matter which can maybe best be described as “what exists is that which exists”. This has zero value logically as it’s a tautology, but it may help to convey the experiential nature of it.