I have now made a playthrough of TLJ on ScummVM 2.5. I made sure to reload and try all dialogue options and watched all FMV scenes, including the ones that differ depending on whether you choose to work an extra shift or not.
My system is a new, midrange laptop with Windows 10. I had the HD upgrade installed, including the FMV files in the highest available resolution.
Almost everything worked perfectly. No audio or video glitches, no police station bug, all FMVs played fine.
There were, however, two minor problems:
1. In chapter 7, inside the floating castle, there is a bug in the second room which makes it impossible to progress. This can be resolved by saving beforing entering, then turning off the HD mod in the ScummVM settings, walking through the room, then turning on the HD mod again. Reentry into the same room works fine with the HD mod.
2. After the game was completed, I could not access the extras from the main menu without turning off then on the HD mod. Although this is not in the game proper, it still is annoying and should be fixed.
When these bugs have been fixed in a ScummVM release, GOG should repackage the install files to include a ScummVM installation, as well as the HD mods. For a lot of people, this would be the easiest way to set everything up.