Attribute lists are a good way to reduce attribute values and to make a search more effective compared to a free text attribute.
Since they reduce the number of wrong entries created by type mismatches.
But in some cases or over the time you may have value lists with a lot of entries (more than a hundred). Then these lists cannot be handled very well anymore within the "modify attribute" window and you need a way to reduce the number of attributes displayed.
So there should be a filter for the displayed attributes (see example under: http://listjs.com/). The filter should reduce the available attributes while you type the filter.
E.g. if you have a list like:
the you should see as you type:
if you don't enter anything you should be able to see all values with a scroll bar (if they cannot be displayed at once)
disk => you should only get offered only: disc, disc(audio), disc(video)
disk(a => you should only get offered only: disc(audio)