The details are here:
https://www.gov.uk/guidance/mot-inspect ... es/updates
The sort of things that you mention, which would be 'Minor Applicable' are:
Important one this as changed on 22 March to include the "on or after 1 April 1986". Previously, in the Jan 2021 list of changes, there was not a date mentioned so anyone fitting LEDs to Halogen conversions would fail.
4.1.4. Headlamps - Compliance with requirements - Changed 'Existing halogen headlamp units should 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.' to '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 not compatible.'
So just fitting LED headlamp bulbs was a fail in a Minor (who knew) but now isn't.
These changes are dated Jan 2021:
0.1. Identification of the vehicle - Registration plates - Sentence changed from 'display white, grey or silver characters on a black background - only on vehicles manufactured before 1 January 1978' to 'display white, grey or silver characters on a black background - only on vehicles manufactured before 1 January 1980'
So no material change there...
1.1.11 Brakes - Rigid brake pipes - Added paragraph 'Repairs to the pressure lines of hydraulic brake systems are unacceptable unless suitable connectors are used. Compression joints of a type using separate ferrules are not suitable.'
Why would you not just change the respective pipeline anyway....
There's a whole load of minor changes to lighting and electrics so have a read yourself. Most of it seems to be to stop confusion from badly worded previous requirements, such as this:
Direction indicators and hazard warning lamps - Compliance with requirements - Changed paragraph from 'On vehicles first used on or after 1 September 1965 with direction indicators combined with position lamps, the position lamp must go out when its direction indicator is flashing. The direction indicator must flash amber only, with no white or red light.'
to 'On vehicles first used on or after 1 September 1965 with direction indicators combined with position lamps, the position lamp may or may not go out when its direction indicator is flashing. The direction indicator must flash amber only, with no white or red light.'
I think that a Magazine article about all these slight wording changes would be relevant to just a handful of people.