I'm trying to create a form that uses a bushy taxonomy of about 30,000 (max depth is ~9) terms to allow users to select multiple nodes from the tree. The Taxonomy Term Reference Tree Widget fits the functionality I need perfectly, but with the size tree that I'm using each expand/collapse or select event takes a couple of seconds to complete, which isn't acceptable in terms of performance.
I'm new to drupal, but haven't been able to find a widget that can perform this task quickly. Are there any D7 widgets or modules that can accomplish this task? It seems that if I were able to have the widget not load all of the children all at once that performance might increase, but I can't say I'm sure.