Thanks, Averdahl, but as I mentioned before, bezier is not helping. No matter how I futz with it, the very end is too abrupt (or the very beginning, in a fade-up), just like it used to be with the video transitions. I'm assuming that the solution with audio will be something like it is with video (a random setting default, like it was with Composite in Linear Video). However, with the video, the answer was easy enough to google, while audio is not, which makes me believe that fewer people are actually noticing the audio abruptness than did the video (which makes sense, considering Premiere is a video editing program). But I'm still hoping I'm not the only one!
Did you make them longer? The shorter they are, the more abrubt they will be, especially if the audio itself is hot.
And, make the audio track as high as possible on the screen since it makes fiddling with bezier handles a lot easier and gives you more control. Alt+Scrolling is your friend here.