Hope this helps. It will only work with local files (as you prefer), JPLAY Overlay, and Squeeze to Squeeze. Also, make sure to set the update time in JPLAY to the maximum (see the last picture).
Material :
JPLAY :
Even though control devices like an iPad or the JPLAY app don’t process audio directly, both software and the hardware they run on can still affect sound quality through their influence on network traffic, timing, and noise. Using optimized connections and setups can lead to noticeable improvements.