Any audiophiles that play League?

I have some issues getting optimal sound quality out of League, and I was wondering if anyone had any sorts of solution already. Normally, I play using an Aune T1 DAC, and some decent-ish headphones I got from work (JBL Everest somethings, not great). Last night I decided to try with my Hifiman HE-400s, and everything was way too shrill. I'm not certain if this is due to sound design (because poor masters often sound harsh through planar magnetic headphones) or if it's due to lack of equalization options (since the HE-400s are really bright on the high end and typically need a kick down at the highest frequencies). Either way my ears were fatigued halfway through an ARAM, and it looks like I'm just going to have to avoid using those headphones when playing, or get a DAC where I can equalize there. Does anyone with a darker/more neutral pair of planars (like the Audeze LCD-2 for example) still experience the same harshness with League?

Side note, I really wish there was a WASAPI mode to give League direct control of my audio device. I hate having to go through the operating system default mixer. Also if I have the client open and then do listen to something in WASAPI exclusive mode, I then lose all sound in the League client afterwards.