I haven't had a chance to look at it closely. What lines did you change?

i have changed checkAppend function and _create.

I see, so you added a container option. Do you have a working example? Maybe you can push these changes to the original repo and I'll see about folding them into the original.

I'm not sure if it has bugs or not since it hasn't been tested yet by other users to left their feedback about this script , so let them first try it and then update the original repo.
Though check my Demo Link with a Live Working Example
http://devian.gr/scrollAppend

Edit: Demo Updated. Source Code Attached.

Updated Feel Free to Check my Demo on previous Post