Due to the conversion, a low latency is certainly present. However, if you use several of these adapters, all streams should have the same latency :)

It can be assumed, since quot: With the Stream Link 4K, you can achieve smooth video recordings without delays and distortions during live streaming, just like with a high-quality webcam. This is guaranteed by a frame rate of 60 fps and Full HD resolution in 1080p (True to Life video quality). The adapter supports high-resolution 4K Ultra HD quality on the input side and is backwards compatible with lower resolutions.

Unfortunately, I can't answer that from experience, as I used it to stream from my camera and it only supports 2K.