Why is the Transcoded Maximum Bitrate Output only 10240Kbps?

Within the Wowza Video platform, we have some limits imposed to ensure streaming is successful. One limit we impose is the output bitrate in the transcoding template like in the example below:
 

In this case, if you require a higher outbound bitrate for the 4K rendition, it is best to "passthrough" the video for this rendition if you desire the output bitrate to be higher than the 10240Kbps limit. 

Resources:
Stream in 4K with Wowza Streaming Video
Transcoding Best Practices in Wowza Streaming Video