Best Plex Alexa and Cast Device Support

Which devices currently work seemlessly with Plex and Alexa. What I want is to be able to always find the device in the Android or iOS cast list and also be able to set the device as a Alexa player. Ive tried roku but it doesnt always show in the Cast list unless the plex app is already running on the Roku. Chromecast doesnt have that issue but it doesnt support Plex Alexa Skill. So what device does everything? Im open to Smart TVs also especially if the Smart TV allows direct YouTube app casting as well.

Thanks.

So I guess there isnt device that supports those 2 features?

AFAIK all of the devices with the exception of the chromecast need to be on and running for it to be exposed in the cast list or to use Alexa.

I get around this limitation with alexa by adding a Harmony hub which I can now tell alexa to open Plex on my fireTV which she does and then use the commands in the skill to control plex.

PS alexa is now capable of linking directly to a firetv device and control it(still limited at this time). Meaning netflix, amazon video, sirius and a few other apps can be launched via voice natively. However last I looked , I could not get plex to launch using this method.