Sorry for the delay, I've been away.
Regarding the android menu, I'm refering to the screen casting option in the general android menu (see attached picture).
Let me start over. If I reboot my phone and open Poweramp, I have no chromecasting icon in Poweramp.
If I open my android menu, enable the screen casting option (see attached picture), the chromecasting icon appears in Poweramp.
With the screen casting option enabled in the android menu, I can play music from whatever app is open on my phone to the chromecast device (Including Poweramp).
If I disable the screen casting option from android menu, then go back to Poweramp, Chromecasting icon of the Poweramp app is there but it doesn't work.
For whatever reason the step described above is not required by VLC to access local music on phone. I immediately see / can chromecast after a reboot.
As mentionned above by Andre and Motley G, I would much prefer having the higher quality audio to chromecast. However I would prefer having transcoded quality from Poweramp then nothing at all, hence my request for an option to default back to the standard way to chromecast.
Thank you for all the help you are providing me to solve the issue