I think it’s funny that you want to do a poll for context but your question itself is context-dependent. Any quality of any human, inherent or adopted, can be a slur in the proper context.
Is ‘trans’ a slur when it’s Elliot Page talking about himself? No.
Is ‘trans’ a slur when a bigot calls someone ‘trans’ to insult them because they think being trans is worthy of contempt? Yes.