I don't know what your specific experience has been but I've never had any issues with any later version in relation to WinForms. The support for WinForms under .NET Framework is exactly the same. For .NET Core 3.1 and .NET 5 and later, the entire WinForms UX was built from scratch, so there are some differences there. That may not have existed in VS 2017, so there's no real comparison there. There are some things missing and some bugs present there but that doesn't affect .NET Framework projects. I suspect that that's the actual difference you're talking about, so upgrading will have no effect there. Things will be the same for .NET Framework and, while not quite as good for .NET Core, that's still better than nothing at all.