No. The Dual Series does not include an internal Mid/Side encoder or decoder matrix.
The front-panel labels simply acknowledge that the unit can be used in either traditional Left/Right stereo operation or as part of an external Mid/Side processing chain. When fed Mid and Side signals from an external encoder, the two channels can be adjusted independently, allowing separate equalization of the Mid and Side components of a stereo signal.
This approach provides maximum flexibility, allowing the Dual Series to integrate with the wide variety of Mid/Side workflows already found in professional studios. Users wishing to perform Mid/Side processing will need an external encoder/decoder, either in hardware or within their DAW.
In standard operation, simply connect and use the unit as a conventional stereo or dual-mono equalizer.