The problem is, that in that case you wrote, it's 4 different plugin sequencer instances, and the whole simplification is that only in case if one is used, the zones work together. E.g if i switch preset, i've got new sequences for arp, and bass, which are matched. In case of 4 instances of this plugin, first of all i must set same preset in each. And i can do that, but i modify this sequecnes, in this way, i must do same thing 4 times, or save/load preset in each - which in the long run is uncomfortable and time consuming (apart from the mass of increasing presets).
The solution which producer of plugin recommended for Logic Pro X, is create a new virtual MIDI cable in OSX, and use "External instrument" in Logic, and etc - BUT i believe that is easier way...