There isn't a way to specify just to print the top of log or just the bottom. We do have a generic log form that doesn't contain and DVIR and we also have a 2-up log that has two log forms on the same page. I could add one of those to your account if you would like. Please send me an email to support@logbook.com if you're interested in taking a look at those forms.
Hope this information helps, please let me know if you have any other questions. Have a great day.