UV wrote:
but I can legally land 25 yards abreast of the same aircraft by landing on the designated grass runway
Bless you, UV, but you can't. Parallel runways require a greater legal separation than this, and unless you comply with this minimum separation, they are legally (within the UK) treated as one runway.
"Land after" applies to parallel runways too, and always only applies with full ATC and with the agreement of the commander of the forward aircraft.
Read the ANO.
Interestingly, the Yanks are looking at full ILS Pub Cat descents on close-in parallel runways (like LAX, DEN etc)...anyone have news?
DT