Hey Hourence,
You’ve unfortunately wondered onto something stuff that is still very much being developed. While the basics more or less work, as you’ve pointed out it clearly lacks the workflow polish needed to be embraced.
We have plans for significant work on these systems, especially since you can’t actually localize audio in the engine at all atm. Unfortunately, we have only one person who works on all that is localization/internationalization and thus some other highly important tasks are blocking progress on the audio systems.
The current plan for the future is to remove the subtitling from SoundWaves and only support subtitling through DialogueWaves. You are not technically forced to create a SoundWave to play a DialogueWave (though I do not know if the subtitles appear on screen like they are supposed to). Creating a development only SoundWave for the DialogueWave will be dramatically smoothed out. We would support quick audio import or automatically generated robot voice.
I said development only because official recordings would come through the localization pipeline and doesn’t require that any pre-existing SoundWaves. This is ideal for development as you only need to create DialogueWaves for each line and don’t have to worry hooking up X number of SoundWaves which vary based on the culture the audio is recorded for.
I’m truly sorry for the trouble, I’ve been pushing very hard to get the resources to fix these systems properly, but it looks like you are going to have to wait a while longer it seems.
We do have this system schedule to get love before the end of the year.
-Justin