Agreed, ontology is philosophy, not physics. It asks, what kinds of things exist? It straddles the line of the empirical and the conceptual, asking, do 'facts' exist, and can there be 'moral facts'? Here be dragons, and epistemology is the treasure.

Physics reports observations of experiments and theoretical work, but wisely leaves epistemology to philosophers - a hard learned lesson. Einstein was ridiculed for his ontological realism, and the trend has been in the opposite direction ever since.

I am interested in brave physicists who have stood up to the epistemologers, and are willing to make ontological commitments. In my understanding, historically, this attitude poses risks to one's career in physics.