In pre-segwit, block header bytes were counted as "1 byte" and participated equally in the block size up to 1MB. Since the header is 80 bytes, we would actually have 999,917 bytes (1,000,000 - 80 header bytes - 3 tx counter bytes) for transactions.
However, what in the case of post-segwit when there is no more calculation at the level of the real byte, but at the level of the WU? Are these header bytes treated as non-segwit bytes, i.e. cost 4 WU, so we actually have 3,999,668 WU (4,000,000 - 320 WU for header - 12 WU for tx counter) for transactions?
Does this then mean that, for example, in this block (click on
Technical details to see all the block properties I'm talking about) the
weight (3,992,825 WU) also includes
320 WU of header bytes and
12 WU of tx counter bytes. Additionally, the
size (1,159,038 bytes) and
stripped size (944,929 bytes) also include
80 bytes of header and
3 bytes of tx counter?