How to properly work with multi-targeting and vscode + devkit?

I'm writing general purpose library and would like to multitarget NETstandard2.0, NET6, NET7, NET8. Only problem is, Intellisense stops working for whatever isn't active context when using conditional preprocessor and I don't even have a clue how to change between contexts other than shuffling them in csproj TargetFrameworks. Any ideas? Thanks.