Hi @Steeler !
Synthetic full will take the last increment that has ben performed and generate a synthfull backup with a timestamp from the day you scheduled this synthfull job.
If the last backup was a full or a synthfull, then it would generate a new restore point from that day, but in reality, the content would be unchanged..
So, if your last incremental backup was performed 5 days ago, then you could be surprised to discover that your Synthfull contains backup data from 5 days earlier..
So, yes, if you want to have a Synthfull that contains data from the day you run it, you have to perform an incremental just before the synthfull.