Video Slider Test
Final Code Block Used (to accommodate 2:3 aspect ratio custom thumbnails uploaded via the slider):
.et_pb_carousel_item .et_pb_video_overlay {
background-size: 100% !important;
}
.et_pb_carousel_item .et_pb_video_overlay {
height: 90%;
}
.et_pb_carousel_item {
background: none;
}