it would be cool if you could split a whole pattern in the pattern matrix, so the first half would be a pattern, and the second half would be a pattern,
There is a tool that does that
http://www.renoise.com/tools/pattern-split-plus
However, you will need to manuallyupgrade the tool, it was created for Renoise 2.6, but I checked and it works for 3.0 as well
Instructions on how to upgrade a tool:
https://forum.renoise.com/t/lua-api-changes-for-2-8-how-to-upgrade-tools/34432