Yeah, there are several workarounds and other ways of doing this.
But for now, I'm just looking to see that WED does what it's supposed to.
Checked the manual and while the "load sound" description states that you can load .wav and .ogg (which is incorrect), the "add sound" states only .wav.

So I'm sure it's either a mistake on Conitec's part in which case we'll be able to add both file formats to the levels or a mistake in the manual, in which case your methods would come into play.