I used to be able to use page up and page down (or Fn+up and Fn+down on my macbook) and it would stop at the top or bottom of a pattern.
Since upgrading it now continues seemlessly to the next pattern, which I actually find annoying when trying to copy patterns.
For what it’s worth, you can also simply hit the End key to jump to the end of the pattern. Similarly, Home will jump to the top. (On a Macbook, I believe these are Fn+Right and Fn+Left respectively, but I’m not 100% certain)
There has never been a mode where it stops at top and bottom once you reach them. Either you will continuously scroll around the same pattern, going from end to start and start to end, or you will continuously scroll through the entire song, changing pattern at start/end until you get to the very beginning or end of the song.
There has quite recently been a request for a mode which stops on the first/last line when scrolling or entering data though…