Improvement on Hook's quick preview window?

Current content quick preview function for a hook bookmark is great, we can preview the content (like PDF) of a bookmark without opening it, hiwever for now the preview window expands not that natural, the preview window will expand after you type space bar, and break the position of Hook window (it should in the middle of the screen), for PDF content, the preview window will even get out of the screen, which is wired, can it just behave like a normal spotlight preview window?