Casting from VLC through Digitab STB

[TheManFromJapan]

Supposedly the new digital STBs have the ability to act as a casting device and I was able to successfully do so with the IOS YouTube app.  All the three boxes appear with the same "Optik TV Client" name which I gather can be changed.

However, this only seems to work on the YouTube app and not on any other media player app that only sees my existing Chromecase device.

Is there anything special about the protocols the STBs use to do casting?  I have confirmed they are on the same network as the iPad (or else the YouTube app wouldn't work either).

[Nighthawk]

YouTube is from Google so it supports casting plus there is a YouTube app on the new Optik set top boxes which is one loophole for it to get around Apple's restrictions on casting. Same goes for Netflix, etc, because there is a version of that on the set top box. VLC is not from Google and doesn't support casting on iOS. Like many apps on iOS it does support Apple's AirPlay, which Google doesn't support natively.