Our strange situation in Italy is that in our general manual (MO-ATM) land after is not considered. It only appears in Fiumicino and Malpensa local manuals, but its applying conditions shouldn't be less restrictive than general. At the contrary, in MO-ATM we have only the RRSM last version, so with new more restrictive conditions.
In my opinion in UK the strange situation is that is not clear in your CAP493 MATS1 para.15.2.4, if "...landing aircraft may be premitted to land..." means that it is a RRSM or land after procedure (you say clear to land or land after??), and also that it is not updated according new RRSM...