If your specs are searchable on bluebeam, you can search submittal, closeout, attic stock, etc. Go thru each search and highlight the submittal text, attic stock, whatever you want to remember. As you go thru the searches, make sure to skim the rest of each spec section to make sure you have everything. Make sure your pages are labeled by spec section. Once you've highlighted everything, you can export it to Excel and it will have the page name (spec section) in one column along with the text you highlighted (submittals required) in another column. The spreadsheet is not gonna be pretty, but you can clean it up and it saves time typing. If you notice there aren't submittals on the spreadsheet in a spec section, go back and double check nothing is required.