Bump on this from my side as well, since this is a very important feature.
It's impossible to create a fade-in - fade-out effect without a middle transparency setting.
I just bought this software and realised that it doesn't support it, quite a let down. This should be a quite minor change into the app to make it work.
Could you please integrate this for us? I'm sure there are a lot of people that would need this, since it's quite a common use case.
Thank you!