Can the Matriarch's sequencer or arpeggiator be set to swing?

Yes. Adding Swing to the playback of the Arpeggiator or Sequencer causes the offbeat to arrive early or late, in varying amounts, to change the rhythmic feel. This can be set by going into the Matriarch’s Global Settings.

GLOBAL SETTINGS:
Most Matriarch front-panel controls relate to creating sound. Below the surface, there is another level of parameters known as the Global Settings, which determine how the instrument operates, and how it can connect and interact with other electronic instruments and audio equipment. To access Matriarch’s Global Settings, simultaneously press and hold the HOLD [SHIFT] button located in the Left-Hand Controller and the SYNC ENABLE button located in Oscillator 1 until the SYNC ENABLE button begins to blink. This indicates that Matriarch is in the Global Settings edit mode. Now you can use the keyboard commands listed below to make any needed changes to the Global Settings. The SYNC ENABLE button will blink a specific number of times to indicate which Global Setting is currently selected. When you have finished making any changes, simply press the SYNC ENABLE button to exit the Global Settings edit mode. Once you are in the Global Settings edit mode, you can freely select different groups and parameters using the black keys, and can switch the value of the selected parameters by using the white keys, until you press the SYNC ENABLE button to exit. Double-tapping on a white key will both update the setting and exit the Global Settings edit mode simultaneously.

HERE’S HOW IT WORKS
Global Settings are organized in groups of ten. An individual parameter in the chosen group is selected using one of the lower 10 black keys, starting with C#0. The white keys, starting with C0, are used to set the value of the chosen parameter. The first 10 parameters are in the default group, and no group selection is required. Additional groups are selected using one of the upper black keys, starting with C#2. To access these additional parameters, hold down the Group Select key while pressing the individual Parameter Select key.

ARP/SEQ SWING

To add Swing to the arpeggiator or sequencer, use any of the white keys to set the swing amount, in 2% increments. The range of available values is from 22% (offbeat at its earliest) using key (C0), to 78% (offbeat at its latest) using key (C4). A Triplet feel, equal to a value of 66%, can be achieved using key (D3). The Default value is 50% (no swing), or key (C2).