There have been many proposed epicene or gender-neutral pronouns that have been proposed over the years and have received some level of use. My question is: do all of them mean the same thing? Are they synonyms for each other? Is it even possible for pronouns to have synonyms?
That is, if a person has indicated that others should refer to them with gender-neutral pronouns, is the choice of which pronoun to use (e.g. singular they, Spivak pronouns, thon, etc.) a question of personal preference, style (e.g. perhaps a specific magazine decides to standardize on using thon for all persons not identifying as “he” or “she”), or pragmatics, or is there a deeper issue of meaning?
For example, is there a pronoun that refers only to transmen, and where use of the pronoun to refer to people who are not transmen (e.g. women or cismen) is to some extent discouraged or considered incorrect?
This question is obviously related to the recent controversy on Stack Exchange, but is intended to be an independent question about the English language and not an attempt to bring the controversy here. To be clear, I’m not asking for opinions on the current controversy. I’m asking if there has been any indication (e.g. through research, or even activism) to indicate that these pronouns have distinct meanings as opposed to simply being preferred or designated by different communities, or recommended based on social, political, or regulatory reasons.