Alpha in KantanMapper?

Hi everyone,

it seems KantanMapper cannot work with alpha channels.
I have several mapped objects, some overlaying the others.
E.g. one on the top layer is not used for the whole show, so I want to hide it, just showing the underlying layer, by assigning an all transparent TOP.
But I don’t succeed, I get a black mask on top of the other…

I am working with a cue system that dynamically assigns and blends TOPs to the different KantanMapper textures, so temporarily deactivating the unneeded mapping masks would not really go together with my cue system…

Any ideas?