Keep in mind that the IR gun method is one tool in your toolbox for the problem. It's good for detecting things like stuck relays, where heat is geneated due to a high-resistance high-current path through a component. It won't tell you about those small-current drains, unfortunately.

As others have suggested, a good ammeter in series with the ground strap is the first weapon, since it sees all current flowing through the battery.

As others have already suggested, you can use each fuse as a resistive element, and detect current flow by looking for voltage drop across each fuse. Using your DMM on a millivolts scale, one probe on each end of a fuse will let you detect where current is flowing. Know that there are a few circuits that don't fuse in the CE panel, some of them have no fuses, and fuse locations in a particular circuit may not always be at the load end. If they are at the load end, there's potential for leakage at upstream components like relays even with the fuse removed.

Since you have the CE panel freshly reinstalled, monitor battery ground strap current as you put relays and fuses back in one by one. I usually try to do this with a low current capacity source, or a small fuse in series. I use a cheap Harbor Freight current tester that has a spot for a fuse in series, so I can limit the amount of damage I do while fiddling with pieces. Tracking down current drains in a 928 desrves more than a single chapter in the DIY Service Manual, way more than will fit in a single RL post.