Ok, so there is definitely a bug with restore point selection for GFS that creates double-active fulls to run when you have copy entire source selected.
It looks like, if you have a restore point selection that is on the next day, but before the next syncronization interval, the copy job runs on both days. If you have the restore point set to the same day as your copy interval starts (but after the start of the interval) it pulls it just on that day.
So in my case, my copy interval on one job is set to sync at 8AM. My GFS point selected was originally at 4AM Sunday. When its sync interval on Saturday started at 9am it would run a full instead of an incremental because the GFS point was during its copy interval. Then, when it started the next interval on Sunday at 9am it would run a full because the GFS point was on the same day of the week. I "resolved" the issue by setting my GFS point to be on Sunday at 10AM before I left the office on Friday. When the job ran yesterday it ran an incremental and today it is finishing off its full.
I still find it worrying that when I set a "choose the restore point closest to 2200 on X-day" (default I think) it does not run the Full AFTER that point in time but before.
But at least I have fixed my issue where my retention was being shot to hell because it was running a full two days in a row.
Veeam Certified Architect