If it's a fairly easy code update, we'll be able to provide the feature sooner. Otherwise, we have it in the medium priority to-do list.
While configuring a new Linux system over the weekend, I learned that I've been stuck on AIJ-3.4 long after version 5 became available, primarily because the default JRE for Ubuntu is quite old. Newer revisions of the JRE are available, and AIJ-5 runs without issue so long as a more current JRE is installed. After a proper update, I see that displayed FITS header data are updated to coincide with the current image while stepping through a sequence. This is very helpful when reviewing occultation sequences.
Sincere thanks to the AIJ developers for responding beyond my expectations. My initial question wasn't intended as a feature request, but only as a call for assistance in case there was a way to configure the program to maintain synchronization between image and header displays that I was not aware of. I have no idea how long ago this enhancement was incorporated into the program code, so apologies for the delay in acknowledging your efforts.
-- Mike --