My lad is a gelding as well, nervousness is not just in mares.
I personaly will happily give my lad a tube of oxyshot if I think it will halp him have an enjoyable experiance. I'd far rather give it to him and then him have a nice experiance as then he will be happier in similar situations. If he gets stressed and nervy then when we are in a similar situation all he will remember is the stress and nerves and it becomes a vicious circle.
I do NOT advocate giving anything like ACP (aka ACE) to a horse but things like oxyshot are different to them, they do not work in the same way or do the same thing to the horse
It would be worth you reading more about them so you understand them better Equine Oxyshot® - The No.1 Instant Calmer