I've had the opposite experience with weird C++ projects from some customers that use external toolchains. For some reason even creating the compile_commands.json file with Bear doesn't work, while the proprietary Intellisense extension works out of the box without any configuration.
I don’t exactly remember how it went but ~5 years ago Goodnotes 5 came out and they offered a “bundle” of Goodnotes 4 and 5 together at the same price of Goodnotes 5. Maybe owners of version 4 had some kind of discount on the bundle because they already owned half of it?