so I often use a single frame dissolve centered on the cut to smooth out audio edits quickly. I could checkerboard the 2 audio clips and then keyframe the level for each clip, but this is much faster. My audio transition default duration is set to 1 second, I can change that to 2 frames (can't set it to 1 frame) and this is not the ideal solution. And, I can't save this is a audio transition preset and although I can copy and paste it, it always starts at transition rather than being centered on the transition and can't seem to change this behavior either in the effects controls as it can only be dragged to start or end at the transition not centered on the transition. What I do now, is apply my default audio transition centered on the edit and then doubleclick on the dissolve in the timeline and change the duration in the dialog to 1 frame... Not ideal, but not a premiere deal breaker, but wondering if there's a better way.
If I "show audio time units" in the timeline hamburger menu, still doesn't help. what's interesting is that I can set the transition duration to 1 frame when it's not enabled, but when I "show audio time units" it shows the transition duration as 2 frames (or thereabouts 00:00:00:02002) but when I turn off "show audio time units" the transition duration is displayed again as 1 frame. I have a feeling it's always a minimum of 2 frames... just some sloppy programming so that it will sometimes display as 1 frame. the difference between a 1 frame audio dissolve and a 2 frame one would be pretty difficult to hear.