I just recentley had a conversation with a SPAC supervisor and was enlightened on the 48 hour routine. After you make the spac case it will do its initial search for 2.5 hours. Once the initial search completes it will not search again until 11:00am the next morning. You can Express Direct between the initial search and 11:00am the next day if you have a dealer who will sell it to you.
You will also never get paid on a SPAC case unless you are able to click commit on the Express screen. SPAC does not have the ability to manually credit you for the sale.
Hope that helps