Stair lighting in the stringer

I would pay attention to the following:
Emission direction and light diffusion - you don’t want to be dazzled.
Heat dissipation - even LEDs operated with DC 12 / 24V produce heat.
Placement of the transformer directly behind the luminaire as a separate element.
Choose luminaires before the cheeks are manufactured so that the cutouts fit 100%.

A WEL Q14 step light with 14 LEDs 1.2W would be an option for me. Just buy a handful more, then replacement over the next 20 years won’t be a problem (specified with 20,000 switching cycles and 30,000 hours of luminous duration). Costs around €20 each. No GU format needed.

It should also be ensured that one can access the cable duct and the transformers later on without having to dismantle the stairs. I speak from painful experience.

It should also be ensured that one can access the cable duct and the transformers later on without having to remove the staircase. I speak from unfortunate experience.

Good point! For many models with a decentralized transformer, the opening for the light fixture itself is sufficient.

Thank you hampshire, that is exactly what I was looking for. Thank you also for the tips. I can work with that.