Microsoft Technologies based on the .NET software framework. Miscellaneous topics that do not fit into specific categories.
What you observed has been there for two decades, due to the internal design of WinForms designer upon CodeDOM. Since CodeDOM was not smart enough to ignore default values and keep everything in order, it was recommended that you don't manually edit the file (because your edits might break CodeDOM and then you cannot easily get things back).
It was only a few weeks ago that Microsoft rolled out a long due upgrade to WinForms designer (sadly only in VS 2022 for .NET Core/.NET based WinForms projects) that switches to Roslyn and you can read more about it in this post
If you like, you can upgrade to VS 2022 Community edition and give it a try.