Can I create a custom SoundSet combining elements from multiple SoundSets?

I’m trying to build or modify a SoundSet based on Otyugh Battle, but include a specific one-shot effect:

  • “Dive Underwater” from the Aboleth Battle SoundSet

My goal is to have both in a single SoundSet so I don’t have to switch mid-session.

I’ve run into conflicting information and UI limitations between:

  • Fantasy Player
  • Online Player (Web Builder)

So my core questions are:

  1. Is it possible to create a custom SoundSet that combines elements from multiple existing SoundSets?
  2. If yes, what is the correct workflow and which tool (Fantasy Player vs Online Player) should I use?
  3. If no, is switching SoundSets the only supported method?

Context: I haven’t used Syrinscape in a few years, so I may be missing a newer workflow.

Thanks in advance!

P.S.
If this isn’t supported, is it something Syrinscape Nova is intended to solve?