@chaley - you are probably already considering it but in you want prompting - would you consider changing the calls behind the formats column so it doesn't touch the disk and instead just uses the formats calibre has recorded in the database for each book? I too have a formats column as it is a darned handy one to have. I don't have enormous startup times by any means, but if I can shave time off without losing functionality that sounds a win to me.
BTW - you are probably also aware that the worst possible thing you can do in a large calibre library is click on the column heading of a formats column to sort it - it takes "forever".
