Not sure why you are mentioning "DLNA renderer" several times while you want to play on your Chromecast.
A DLNA TV is a DLNA Renderer. A Chromecast isn't: it is a Chromecast. Which can be standalone (ie Google models) or embedded in a TV. A TV can support both DLNA and Chromecast embedded (and would be listed as 2 renderers in BubbleUPnP).
Transcoding is supported only for Chromecast (all models).
To play videos to Chromecast with Android BubbleUPnP eventually transcoded by 'BubbleUPnP Server' is rather simple:
- make sure 'BubbleUPnP Server' is running on a suitable machine on your home network
in Android BubbleUPnP:
- verify that 'BubbleUPnP Server' is detected in More > Gear icon > Chromecast transcoding > Transcoding method
- in the Now Playing tab, tap the floating cast icon to select your Chromecast as current renderer, if needed
- play a video either browsing the Library tab, or sharing a video from a third party app. Rarely you need to use "Add Stream URL". Only if such URL cannot be passed another way.
=> If all goes well the video should play on your Chromecast, and if is transcoded, it will be mentioned in the Now Playing tab below the seek bar.