In the Qtractor arranger we have inserted the 16 key pattern, where you can switch from pattern to pattern, like one standard arranger.
Qtractor have also the midi editor clip ( piano roll) for imput notes like one drum machine system.
You can configure the patterns how you like, can be only one midi tracks or audio tracks, you can choose what you will do for the each 16 patterns.
We think that this is the best way and full editing system for the arranger mode too.