Scrapbook File Format Question

Since I still have some questions about the Paulus scrapbook foldouts, today I focused on editing the Kappa Sigma scrapbook scans. I'm well over 3/4 of the way done with editing them in Photoshop however I realized I've been editing the JPEGs that were saved as default by BookDrive.

After some research online, I found out that it might have been better to export the files as TIFFs, edit those, and then convert the TIFFs to JPEGs in order to have high-quality of both file types. I know this project is time-sensitive so is this a problem? Do the final files need to be in TIFF and JPEG format or will the JPEGs suffice? If I should start over and edit all the TIFF files instead, I can maybe work some extra hours next week since I know they'd like this completed by the end of the month.

Also, I made the same mistake by editing the default JPEGs of the Paulus foldout scans. However, from the instructions, I understood that there were only three foldouts to be scanned so these will be much easier to export as TIFFs, re-edit, and then convert to JPEG. Are the Paulus foldout scans time-sensitive as well?