Great post!
Well written and easy to understand for average home theatre owner
In europe we adhere to EBU standards whilst america use ATSC although as I understand it they are very silimar and only about 1db different to each other
EBU128 (our TV standard) is as you stated but also allows a short term loudness of -18dbfs along side the average loudness of -23dbfs
Netflix mix spec is -27dbfs at 79db(c) or 82db(c) listening position (guide rather than strict rule to allow for mix engineer some preference based on room size)
I would expect these are all to db(c) levels as the C curve reasonably closely resembles the X curve target of large scale cinema sound system voicing