There is now a third lane (only for buses and bicycles) alongside the park until the intersection with "chemin de la Cense".
(Some land from the park was taken, the sidewalk was moved there and the former sidewalk and streetside parking was turned into a third lane.)

Many buildings in the area are tagged as part of 1420 Braine-l'Alleud (nl: Eigenbrakel), but they are in 1410 Waterloo. Could it be bulk edited by someone?

The street here is still "Rue de la légère Eau".
Right now, "Rue de la légère Eau" is split in two unconnected parts, because "Rue Batty Gigot" starts too early.

A church is a building in a monastery; the two are therefore different things. Could someone split the buildings (I tried and failed)? That way the information can be attributed to the correct point/building. Thank you!

There is a footpath here, similar to the one on the other side, but with the stairs on the left and the pathway on the right alongside the platform. It is accessible to people using a wheelchair.
When you stand facing the trainway platform, and with your back to the street, on your left, the (missing) path ends on platform 1, and so do the stairs. To go back to the curb, there are 3 steps down (with a handrail).

accès PMR (Personne à Mobilité Réduite) entre le trottoir et le quai 1 de la gare de Braine-l'Alleud. (Pas de marche, légère pente, large, pavés plats.)
Persons with Reduced Mobility (PRM) entrance.