SQL BulkLoader was my first attempt at multi-targetting a nuget package.
https://github.com/JasonDV/SQLBulkLoader
There are some interesting best practices around this concept.
https://docs.microsoft.com/en-us/dotnet/standard/library-guidance/cross-platform-targeting
Normally, when working on line-of-business applications, I have a lot of control over what .NET target I’m using. I choose mostly based on which targets are current and what is installed on the deployment infrastructure. Getting configuration changes to deployment environments is often time consuming; therefore, I avoid it unless upgrades justify the time.
In the future, I’ll explore some of my justifications when putting together a solution and choosing technologies, structure, and environment.