[Duplicate of #82] Regionalize effect is missing (?)

In older versions of Kdenlive (before timeline refactoring I think) you could create some kind of "mask" in something like GIMP to create effect regions which basically means you could apply effects to an specific part of a clip (you could even use gradients!) as shown in this video.

However in newer versions of Kdenlive I'm not even able to reproduce that effect, the regionalize effect simply does not show up after adding the "mask" which makes me believe it has been removed in the refactoring process or it has not been reimplemented properly (and even before that the "mask" had to be added twice for some weird reason).

EDIT: If it helps I think the MLT filter is called region.

EDIT 2: The effect xml file is in the source code.