I hope you are well! I have been spending quite a bit of time doing “gain automation” in Logic Pro X on the background vocals. After adding the effects, there was distortion in passages. This “stuff” is fixable, but time consuming and tedious if you do it too long. For me, that is about 60 to 90 minutes. Now, I had recorded each vocal track (6) with a little compression on an “outboard” piece of equipment (dbx) and utilized the noise gate in the unit as well to keep the tracks as “clean” as possible. I did not record the tracks “too hot”. I had read that tracks should be recorded at -18db using a DAW and I thought at the time, that sounds crazy low. Well, trust this now…it isn’t. Each effect or plug-in can significantly change the volume and push the sound into a distorted zone. Gain is on entry side or it is the sound level before it goes to any effects. Volume is the level after all the effects. Whenever I record moving forward, I will be carefully checking and correcting any “gain” issues before I spend time on the tonal qualities. Use a compressor before and after any EQing…that made a huge difference in the clarity of the vocals and the natural sound of them. I have used the “Pitch Flex” tool also in regards to “smoothing out” a vocal. In sustaining a note, you may hear a fluttering in the pitch. Now, performing live, one may not even notice the variance and it happens so fast its done before it would even register being an issue. But, in a DAW environment, when you are listening to the track on its own…when you really do critical listening…these variances maybe something you may want to fix. In the Flex Pitch mode you can use the scissor tool and create sections of the problem areas, which may only be a second of sound. Then each section can be corrected as needed. I would have never thought these things would be needed…but, we are human and no matter how good of a singer you are…you are not a machine…thankfully. Stay well!