Usage/Docs Clarity for re-using animations in series

I've just been playing around with Motion UI for an upcoming internal training session for our move back to Foundation 6. One thing I'm noticing is that I have a block of code like this:

``` scss
@include mui-series {
.card-inner { @include mui-queue(2s, 2s, slide($direction: right)); }
.card-img { @include mui-queue(1s, 0s, fade); }
.card-title { @include mui-queue(1s, 2s, slide($direction: right)); }
.card-text { @include mui-queue(2s, 0s, fade, spin($direction: ccw), slide($direction: up)); }
}
```

The lines to note are the `.card-inner` and `.card-title` which are using the same animation, just staggered slightly apart. When I look at the compiled css, I'm seeing this:

``` scss
.card-inner {
-webkit-animation-name: slide-in-right-100;
animation-name: slide-in-right-100;
-webkit-animation-duration: 2s;
animation-duration: 2s;
-webkit-animation-delay: 0s;
animation-delay: 0s; }

@-webkit-keyframes slide-in-right-100 {
0% {
-webkit-transform: translateX(-100%);
transform: translateX(-100%); }
100% {
-webkit-transform: translateX(0);
transform: translateX(0); } }

@keyframes slide-in-right-100 {
0% {
-webkit-transform: translateX(-100%);
transform: translateX(-100%); }
100% {
-webkit-transform: translateX(0);
transform: translateX(0); } }
```

and then about 20 lines below:

``` scss
.card-title {
-webkit-animation-name: slide-in-right-100;
animation-name: slide-in-right-100;
-webkit-animation-duration: 1s;
animation-duration: 1s;
-webkit-animation-delay: 5s;
animation-delay: 5s; }

@keyframes slide-in-right-100 {
0% {
-webkit-transform: translateX(-100%);
transform: translateX(-100%); }
100% {
-webkit-transform: translateX(0);
transform: translateX(0); } }
```

Is there a reason this is being duplicated? The third `slide-in-right-100` seems like it shouldn't be there considering it already exists above. I hesitate to call this a bug, because an extra 7 lines in a css file is not a big deal, but it seems like this should be done.

However, the main reason I'm posting this issue is to find out if there is a better way using motion-ui to re-use animations inside of a series-based functionality like this? The docs are good for basic functionality, but get a little bit hazy when you're trying to do more robust animation work. From looking at the source it doesn't look like I can pass an already-created keyframe animation in?