I've had a quick look and our middle alignment mode seems iterate through the items on that row aligning them all by their average Y value. Considering that, it makes sense that it would cause an issue with largly varying view heights. Tom's suggestion would solve the issue of overlapping, but I understand that it could also create unwanted space between rows.
I've raised this as an issue in our backlog, and we'll reassess how this layout mode works, and consider what is missing from our API to allow you to get the behaviour you're after. In the meanwhile, I think I may have an idea for a workaround on your end, although it's a very high level idea!
Since this problem comes from the way we look at your managed view's frames. I think you may be able to work around this by cleverly wrapping your IP Camera Video Feed views in another UIView. You'd need to place your IP Camera Video Feeds inside of a wrapper UIView, and make sure that the height of these wrapper UIViews is the same height as your largest Camera feed, and is consistent on each row. Then, when we calculate our average Y value, it should average the Y value of all of the wrapper views on that row. Since all the wrapper views per row are the same height as your largest IP Camera Video feed for that row, you shouldn't get any overlap when we do our alignment calculations.
I understand that this may be a little complex, unless you know the ordering of your feeds before hand. Hopefully my explanation above will give you some ideas in terms of work-arounds, until we get a chance to assess our API.
I'd be happy to help you with any further problems you might have.