I've noticed this quite a few times. I usually download offline installers through galaxy to avoid downloading twice.

I have noticed that whenever I install a game using the offline installers, Galaxy usually downloads some kind of update, sometimes a few MB, other times 100+ MB. Does anyone know why? Does that mean that, in theory, I couldn't launch the games without galaxy with these small updates missing?

Just installed The Witcher 3 from my offline installer backup and now Galaxy is downloading 11.74GB in an update. I have the same version (1.32) that is available for download now, so it should be the latest, I presume?

What's the point of being able to download an offline installer if you can't keep it updated without the launcher?

For me, it isn't completely DRM-free if you need a launcher to get an update over the latest offline backup available.