From the MOT manual:
Existing halogen headlamp units on vehicles first used on or after 1 April 1986 must not be converted to be used with high intensity discharge (HID) or light emitting diode (LED) bulbs. If such a conversion has been done, you must fail the headlamp for light source and lamp...
Never heard of them being called 'abrasive additives' before.
SAPS stands for Sulphated Ash, Phosphorous and Sulphur and the spec just limits the amounts of these that can be included in the oil as they can poison exhaust treatment devices when burnt.
Low SAPS oils just use different chemical...
From what I've heard and experienced it's the oil pump drive chain that snaps first and the cam drive one doesn't.
Mine snapped at about 50mph and I knew what it was straight away and so immediately killed the engine. This saved the engine and it ran it for many years after a new chain but...