Hi Anthony,
Based on my research and tests, it not yet available to manually immediately send emails
set to delay send. To change the settings for a specific email, please kindly go to Outbox and find the email you would like to send immediately, then go to Options > Delay Delivery, as you mentioned in your post.
We value every one of our customers and are trying our best to provide you the best experience with Microsoft possible. If you would like to have this feature enabled and help us improve Outlook, please kindly take a moment and post your
feedback on our Outlook UserVoice Forum, where our engineers check fresh ideas posted by our customers and will take actions accordingly. Thank you for your understanding and cooperation.
Best regards,
Jasmine