Unlike most I only use plex server on my NAS to store and stream my audio collection via Plexamp. I would love to see direct plexamp integration with stereo receivers so that we can still take advantage of gapless playback and other plexamp features. Linked below was a response made regarding this which would be an excellent approach if you would only give me the link to the hardware device you are selling that allows me to just buy and plug in. 
You can check out the Plexamp āheadlessā client which can run on a Raspberry Pi. Thereās a wide range of those available in various configurationsā¦ some are bare boards, others are available for specialized use cases having built-in audio connectors / cases (not an expert, but the linked thread is mentioning HIFIberry).
None of those are sold/offered by Plex.
https://www.plex.tv/media-server-downloads/?cat=headless&plat=raspberry-pi#plex-plexamp
The Feature Suggestions category isnāt targeted for integration requests to specific platforms. As elan pointed out, such partnerships can be complicated.
And if you want examples of audiocards, and other things, and want an easy way to install, look here: https://github.com/odinb/bash-plexamp-installer
There is no official, branded hardware device sold by Plex for direct connection to receivers. The recommended āescape hatchā to achieve gapless Plexamp playback on a stereo receiver is using a headless Raspberry Pi. This DIY approach allows you to plug it directly into your receiver via optical or audio inputs.
