The way the zips work is that they have a StreamingAssets folder in them, which can be extracted into the incarnasoul_data subfolder to put the files alongside any already present.
The folder is different on macs ("/(user folder)/Library/Application Support/tl/Incarnasoul/") but should work the same.
If the in game downloads aren't working, it might be Mega's download limit? It resets each day I believe.