no the issues is the current cycle mode system, you cant trigger just one animation have it play and stop when it is finished. this is because your looping mode is not applicable to each individual animation but rather to the animation list itself.
the developers need to look at the legacy animation system of unity for an idea of structure . You have an animation component and you have animation clips. Animation clips have there own looping mode. So it is possible to set some to play only once and at the same time for other clips you can tell them them to loop. You assign the animation clip to the animation component. You control the animation clip though the animation component but it respects the local looping mode of each clip.
you guys are half way there since the animation list resembles the animation component. You just need to add a looping mode to each clip.
Also for seekTo in the viewer you can pause and drag the slider to the very end and you end up on the last keyframe. Via the api if you set the seekto to the duration , it loops back on itself, it does not stop at the last keyframe.