Answer
The SES defines the directions where the F.4.3.5c is being enforced.
For 2020, teams have the options of meeting the 50% requirement at 90 degrees, or at +60 and -60 degrees.
If the SES tool is not throwing a REJECT code for your layup, it is most likely acceptable.
We discourage any extremely low values.
A CHECK readout below 50% could point to a failure of G.1.4 Good Engineering practice.
For example, ply choices and directions to minimize strength except for the 0 and 90 directions.
Many sensible and acceptable layups for 2020 we tested returned a CHECK readout (below 50%).