The YS is not a low temp industrial machine, it's engineered primarily to fit through double doors of equipment room! It has fixed VI, alarms and trip points are non adjustable to accommodate high compression ratios. So you have to put lots of bells and whistles to make it work half ass. Without liquid injection,better oil cooler, hot gas bypass 50 degrees superheat common.
The discharge superheat derived from the OPs readings were at much less than full load. Discharge superheat readings are intended to be taken at full load. We don't know what the actual load was at the time, but with 30% slide valve and 2° through the evaporator I think it's safe to assume that the load wasn't anywhere near full load. Once that machine loads up I think the OP will see very different discharge superheat readings.