In this thread it is suggested that the HE6se V2 should not be driven directly from speaker taps as one of poster’s drivers died within four months. Higher up in the thread he stated that the drivers are different than in the original HE6, which were okay to drive directly from speaker taps. In the thread they offer suggested resistor values of 25Ω in series and 10Ω in parallel for driver protection and impedance matching to assist in presenting a more balanced load to avoid adverse frequency anomalies. Also, they point out that there is a HiFiMan HE adapter for a quick fix solution.
At the bottom of the thread MrAyrit received a response directly from HiFiMan that the drivers can sustain damage when directly driven from speaker taps.
Here is very good resistor calculator if one wishes to diy a speaker to headphone adapter: