One of the questions asked during the presentation was regarding the sharing of a TMC between systems running different releases of CA 1.
That is NOT a problem, and you can share a TMC with a 12.0, 12.6 without problems. And the same will be true with r14.0 as well; sharing a TMC with either a 12.0 or 12.6 system. However, you will not be able to exploit some of the newest features until all systems sharing the TMC and AUDIT file have been upgraded to support the new feature. But, as long as you are not making an attempt to exploit the new feature, no problem sharing the TMC and AUDIT files.