I did some tests here (in RGBA-8bit) with Reroute, and Alpha Channel. It seems to work correctly. It is time consuming, for me, to post here the screencast/screenshot of the tests, but if you think it can be useful tell me.
It may be (surely) that Cin-CV and Cin-GG work slightly differently.  I remember that, when you are using Title effect, the black colour is meant to be the alpha channel (more or less).
It may be that not everything Cin-CV is able to do can be reproduced in Cin-GG,... and vice versa.