Can spellcasters try to make it difficult to identify what spell they’re casting?

How to identify a spell being cast? discusses how to identify a spell.

This question seeks to discover whether there are steps a spellcaster could take during casting to make this identification more difficult. The question is not about hiding the casting (such as casting the spell round a corner, then releasing it with a reaction) – the person trying to identify the spell has full view of the spellcaster casting it.

Such steps might include:

  • Putting some irrelevant words around the actual mystic words of the verbal component
  • Waving your hands as if performing a somatic component, despite the spell not having one

Is this sort of thing possible while casting a spell (to be clear, without any special capability such as the Sorcerer’s Subtle Spell), and if so what effects does doing so have on spell identification?