I would like to propose to an idea that I think would really help a lot of Synfig users.
I was working on an animation today and I was trying to loop a sound effect, but it seems that looping a Sound Layer isn’t possible. I think this would be a great addition to 1.4.2 or whatever, and maybe add some audio effects, like “fade in,” “fade out,” or make it so you can have it play a certain amount of time.