MPCs have always had the ability to sequence linear or via chaining loops together. Today's hybrid MPC software + controllers offer the same but with the advantages of a greater visual representation of your compositions as seen in today's traditional DAWs:
As an alternative to creating sequence loops, copying them to other sequences, and then chaining them in song mode......I use the Ren/Studio to do this within a single sequence.
So where Producer X would copy Sequence 1 to Sequence 2 then work on a variation....I would copy Bars 1-4 to Bars 5-8 (equivalent of Producer X's Sequence 2) within Sequence 1. Then set the Ren/Studio's sequencer to Loop bars 5-8. Since it is still the same sequence, I don't have to attempt to duplicate track mixer settings, effects, etc. If I decide I want to re-arrange a composition, I can select a region in one or multiple tracks and move it or paste it to another location within a track as seen in the pic above.
And even sweeter...chaining multiple sequences together is still an option. Having flexibility....getting creative...coming up with your own unique way to work....you have to love it.