listbox w/ virtual scroll or multiselect w/o dropdown?

[pianojet]

I'm optimizing a data-entry application that has highly populated listboxes. Multiselect works great for this, except it forces an extra, useless click on a dropdown. Because of the volume of data-entry in this application, that extra dropdown can't work.

So, it seems a p-listbox that supports virtual scroll, or a multiselect that supports disappearing the dropdown, would be helpful.

Any advice? Thanks!