I have got about 500 categories in edocman component on my page.
Every time when I create another one, I have to find parent category for this. This is very hard to do and takes a lot of time. To make it easier, You should change this field to look and act more like category field in new article form. There is a nice search engine and its easier to find what I'm looking for.
If I understand correctly, you want "chosen" behavior for the categories dropdown. Could you please make a screenshot of the field you want so that I can be sure that I understand what you need correctly ?
It's multifunction field - I can search through categories by search field or pick a category manually.
I suppouse it should be easy to addapt to Your component.