Time4Tea: I think that one is a matter of opinion, tbh. As SlackR84 mentioned, some might see it as annoying to have to unzip a zip file just to get to a pdf. I agree it would be nice though, if you could right-click and open the pdf in a new browser tab.
Of course, but as things currently are it might be better to have zip files. Don't think I have ever read anyone complaining about them here at GOG, and they have a much bigger customer base.
Anyway, it is not an issue for me, and being able to open in another tab is certainly good enough, and with PDFs you usually have a save option, and at that point while displaying in your browser it has already downloaded, so only a little extra fuss to do a save to another location. But I guess, if people don't like to do the extra unzipping, I guess they might not like doing the extra saving as well. Who knows.
SlackR84: Yes I know, but inno doesn't support 4GB files. It must be a gog modified version of inno. Post above has the documentation from inno saying 2GB is the max.
Mmmm that is a bit strange, and I wonder why they have that limitation.
I know they do cater for GOG, with some extra specific switches (parameters), as they are listed in InnoExtract.
Perhaps InnoSetup provided GOG with a special version that does 4 GB splits or there is a secret switch for that ... or as you say, GOG have modified it themselves. There is also some RAR element to it I believe. So perhaps the RAR element is doing the 4 GB files.