Just submitted m first round of updates identifying connected covers in the Item Description field, mostly Ptych covers, but some twin and overlapping covers, too.
This update identifies 1,389 issues across 410 separate sets, including both the individual covers and the full image covers that I found.
I will post the collected oddities for this round (sets with unidentified pieces, sets with inconsistent Cover Artist attributions, etc.) after they get accepted, as it will be easier for others to help when the set identifications are available to all.
There are still Notes and Item Descriptions that include notations that may or may not be identifying additional cover sets; I decided to process what I had and submit before continuing.