[ethn]

>If you really did mean to imply that an ideal Santa Claus literally exists in a literal universe of perfect ideal forms

In philosophy, this is "Platonic Realism" quite different from "platonic", the lower case helps convey information. You make a mistake by assuming "platonic" explicitly conveys "Platonic Realism", given there are many "Platonic *" theories, such as "Platonic Idealism". Because of the ambiguity, as you correctly acknowledge, you are expected to understand it as the wikipedia article on "Platonic" suggests (as some sort of abstract object): https://en.wikipedia.org/wiki/Platonic

"Plato's influence on Western culture was so profound that several different concepts are linked by being called "Platonic" or Platonist, for accepting some assumptions of Platonism, but which do not imply acceptance of that philosophy as a whole."

[danbruc]

I still tend to argue that the use of »platonic» or »Platonic« most of the time implies a relation to the philosophy of Plato, the usage with the generalized meaning of something along the line of »abstract« seems to be at least quite rare. The quote from Wikipedia also seems to support this.

And that is of course why I interpreted the combination of »platonic« and »Santa Claus« as hinting at Platonic Realism, because of the implied relation to the ideas of Plato and the example of »Santa Claus« as an abstract idea. Are there any other parts to his work were »Santa Claus« could be a relevant example but that is not related to his theory of ideal forms?

Also »Platonic Realism« and »Platonic Idealism« are, as far as I can tell, the same thing. »Platonic Realism« seems to be the common term, »Platonic Idealism« seems to be a less frequently used term with its origin in the fact that Plato called his abstract objects ideal forms.

[ethn]

"Plato's influence on Western culture was so profound that several different concepts are linked by being called "Platonic" or Platonist, for accepting some assumptions of Platonism, but which do not imply acceptance of that philosophy as a whole."

Does not support that the "Platonic" is Platonic Realism, which is what your chief claim is and what it would implicate if the term conveyed acceptance of the entire philosophy. It merely means the acceptance of an ontology of abstractions—which is implicit when there is discussion of it, otherwise how would it be discussed?

Even if you believe Platonic Idealism and Realism are the same (which is usually meant to designate the classification between 'soft' and 'hard' Platonism), there are even different Platonic periods.

Nonetheless, it's clear that I didn't communicate this well if I'm in this conversation. Which I don't think is irrational since my discussions are usually restricted to academic contexts where this usage is ostensibly vernacular.