My initial impressions with a trial of Fidelia are poor!!!
It displays the K System metering plug-in just fine but locks up playing CD's directly and it's volume control does not function when using the optical output to external DAC (mute and dim do work though). It's current version is intended for files ripped to a hard drive library. I've got many discs that I don't want to rip to a drive and only want to play them occasionally. Currently Fidelia doesn't support legacy HDCD, SACD, DVD-Audio or DSD discs so I'll be looking to try out Audirvana next but it doesn't look like Audirvana supports plug-ins at all.