I think the Technology section is where there are threads about it.
https://forum.blu-ray.com/forumdisplay.php?f=24
eg.
https://forum.blu-ray.com/showthread.php?t=97040
and
https://forum.blu-ray.com/showthread.php?t=59646
[do search in technology section for 500GB for some more threads]
For long shows/movies or many things on the same disc, at very high bitrates it would be great.