I discussed that already with Mnemonic via mail but for the community I post the complete idea behind:
Erm, we play a standard talk animation. Over this talk animation we want to overlay a short anim which contains way more movement in the arms, but it is only an arm animation the rest WME shall take from the standard anim, achieved by removing all the other keys. WME plays this channel very fine till the end of the talk line and than via stopanimchannel the channel gets erased, the talk stops and the character starts to idle. This is when the channeled anim is loopable.
But imagine the channeled anim has a very hard motion something like the arm is raised to the air and than the arm is going back to a neutral pose, but the talk line ends right in the highest point of the arm. WME makes in this case a hard cut and the anim looks like cutted or created by an idiot.
Next way: A non loopable anim in the channel. In this case WME runs the channeled anim till its end, but if the talk line is longer, the whole arm anim gets freezed till the end of the talkline. If the talk line is very short, the same thing occurs as like in the loopable the anim looks cutted.
What we want is, that we use only non loopable anims for the channel. In our example the arms rise one time than go back and thats the end of the channeled anim and WME continues only with the standard talk anim.
So it would be cool if there is any way, that WME recognizes the end of the channeled anim and erases it after the end without giving a da** about the end of the talkline. When the talk line is longer, only the standard channel continues playing, if the talk line is shorter the actors starts to idle but the channel runs till the end of the channeled anim so the arms go back as animated and not as
cutted, then the channeled anim gets erased out of the channel.