Has anyone modded Audacity?

[Selestial]

My friends and I have been using Audacity for years and I moved away from specifically recording in it a few years ago for Audition because of a lack of one simple feature. I never found a way to record over mistakes. Audacity puts a black line at the very end of the recording to start at the end, but other programs I've used will just bulldoze over the already existing audio replacing it with the new one. OcenAudio calls this overdubbing and I don't think there's a word for it in Audition. I've always wanted Audacity to have this feature, but I've looked through the manual and through all of the settings for years and I could never get it to do this. Has anyone ever modded Audacity to behave in this way? If so, could you share how you did it?

[Selestial]

Scratch that, I got the information from somewhere else, but now I have a smaller issue. Audacity seems to put a clip line sometimes and not other times and now I need to know why. Audacity, you make me pull my hair out.