We only drop a 2 core (red/white) from the light fitting here (no neutral or earth required for the dropper) for a single switch with lights having a 3 core TPE running from light fitting to light fitting, with a loop at the light for the two core dropper to the switch (that took some getting used to- all backboxes/switch boxes etc here are plastic, switches have no earth and are effectively 'double insulated' with no exposed metal pentrating the enclosure)Essentially the ceiling roses are replaced with jb's and instead of a T&E down to the switch you drop a three core & E . Now you use the Grey instead of the Blue for the neutral and Brown live with Black switched to light.
The bonus is that we have Wago connectors and no longer need that horrible chocolate block we had for decades, also if used in the right enclosure they are maintenance free.
Note that although those are again BC batten bases, the same applies for LED lamps, fluros. downlights etc- in both you can see the 'red and white' switch dropper, with the reds connected together in the 'loop' terminal- a 'spare' connection point that doesn't electrically connect to anything- its just an 'inbuilt joiner' block for allowing the joining of the droppers without the need for a seperate junction box...