Reverse dependency - only taken in account if defined on the build configuration used for triggering the build

Our build chain is as follow (A first element / C last element):

C depends on B1 and B2
B1 depends on A
B2 depends on A

A is a localization process with a parameter TargetLanguage (by default German).
B1 will just be a localization runner, defining a reverse for TargetLanguage - Portuguese
B2 will just be a localization runner, defining a reverse for TargetLanguage - Chinese
C will collect artifacts from B1 & B2 to put them together.

Triggering C should trigger by dependency B1 & B2, they will on their turn trigger A.
I will expect B1 to trigger A with TargetLanguage overriden, being Portuguese and B2 with Chinese.

A is always launched with Target Language German - the default value.
The reverse overrides from B1 & B2 are ignored.

If I trigger B1 instead of C, in that case the reverse dependency is taken in account.

Is there any limitation to have the reverse dependencies only defined on the configuration build that is triggered ?