What's the point of transcoding to HEVC? If your playback device already supports it, and the file is already HEVC, then there's no need to transcode. And there's no benefit I'm aware of in transcoding from an older format like H.264 to HEVC. AFAIK, every device that supports HEVC media also supports H.264 as well.
It would be helpful to understand your specific use cases in more detail, particularly for batch transcoding (my understanding is that this solution is not about stream transcoding).
Aight have you tried transcoding a normal file (today that means 4K resolution) to H264? It usually won't play because the standard limits resolution to 2048 pixels.
It would be helpful to understand your specific use cases in more detail, particularly for batch transcoding (my understanding is that this solution is not about stream transcoding).