I think almost all, (maybe all of them?) NLE use the same method to to make a J/L cut in the timeline, including VEGAS Pro. You need to Un-group them first, drag one of the clip or audio to create L or J shape, regroup them and merge it with other event. The grouping part required extra steps and sometimes you accidently shift the audio from the visuals causing offset/un-sync media. Yes you can argue VEGAS Pro and even some other NLE have a Offset indicator (Red color with minus sign) to tell you the event is slip few millisecond or Frame, but what if the audio ur using is from different recorder?

So I came out with J/L Cut system. If you hover you're mouse at the edge of the event, you either get Trim/Crossfade or Snapping offset. I personally never use the snapping offset function. Maybe what VEGAS Team can do is, 50% bottom section of the event for both Video & Audio will read the mouse cursor as J/L cut function. So editor can pull or push only the video or audio without even need to Ungroup the media.

This will significantly reduce editing mistakes like forgotten to re-group the event, and speed up the editing workflow.

I use J/L cut alot on my tutorial video.