well, you could still just run the installer using wine, or not? Running the installer also has the advantage that it will create any registry entries that the game may need. You won't get those if you extract the content manually.
Yes, running the installer through WINE still works for me. But like you’ve seen from other posts, it’s not working for everyone. WINE can not be taken as a reliable mean to access the installers contents, as its efficiency can vary greatly from one setup to another.
innoextract on the other side is reliable (innounp might be too, I didn’t study it fully yet)… Or at least it was until now. These new installers incompatible with innoextract aren’t perennial like the previous were: I’m depending either on future Windows version to not break the compatibility (I wouldn’t bet on this, seeing that it’s precisely Windows poor retro-compatibility that bring us GOG in the first place), or on WINE, which as you can see from other posts is no more reliable.
That lets me depending on GOG updating the installers to take care of the compatibility with future Windows version. If GOG shut down, I’m let with installers doomed to be unusable at some point in the future. A situation no better than the Valve one.
We’re not facing a "Linux-only" kind of problem here.