The audio editor in 3.0 has so far been the worst issue for me.
Here's a list of the issues I've noticed so far–

1. The cut, copy, and paste buttons are gone. These are some of the most useful options, too! Scratch has always encouraged things such as MAPs, but this makes MAP making really complicated, frustrating, and just not worth the time and effort.

2. Mid-cropping is gone as well. What I mean is the option to go into the middle and crop something out. This is very useful for shortening songs, taking out a section or a screwup in an audio clip, and, as mentioned before, MAPs.

3. Moving the playbar is gone! I mean, what the heck? I have to listen through the whole clip to make sure a section at the end isn't messed up? It's pretty irritating, and even time-consuming if you're using a longer clip. I know there's a work-around with the trim tool, but it really wouldn't hurt to make it a little more convenient.

4. This wasn't in 3.0 (I think), but being able to zoom in and out of the sound window for exact cropping would be nice– not that it's a necessity like some of the others.

If you have any more, feel free to add on.

Definite support! I miss having those options, and (and I'm not saying I want this) I would rather have the 2.0 audio tab than the 3.0 tab if I had a choice.

S to the U to the double P to the O R T!

I think it's self explanatory.

Support! (although I think the ST is already working on this (not sure))

The Scratch Team is working on this.

ceebee wrote:

The sound editor should have the same editing capabilities as it did in 2.0: We realize that the sound editing capabilities are important to you, and it is a priority for us to include this again. It may take us some time to change this, so your patience is greatly appreciated.

Source

I support this! Something else I noted: the sound quality in Scratch is infuriating. Whenever I import one of my covers into Scratch, the audio worsens, turning a bit tinny, compared to the audio on the original music software. It's subtle, but it's still noticeable. Since I tend to deal with both sounds and images in my projects, it's extremely frustrating. There's also the fact that sometimes the sounds won't load at all, and I get a blank audio. Usually it works after a few tries, but it still takes a lot of time and patience.

1. to 3. has been implemented in August '19, so we only have 4. left now.

I made a suggestion with about the same requests the other day but it got rejected. Somebody shared this link to me to has the features you want. It was going to be put in 3.0 but it didn't make it. https://sheeptester.github.io/javascripts/audio-editor/