Blend video projectors using 'multiply' rather than 'additive' mode

  • Is it possible to blend two or more videos together using a 'multiply' blending mode. The projector just has transparency or additive but I'm wanting the white parts of the top image to be transparent only as in 'multiply'.

    I see it's available in the Effect Mixer actor (mode: mult) but I'm wanting to have more than two videos overlapping with this mode.

    Any ideas?