I'll throw this in for anyone that still comes across this:

Some (many?) companies can be wary of using open source technology because of fear of abandonment, lack of support, and so on. It always helps to check if a certain solution offers commercial support or some sort of paid offering (which is one of the benefits of commercial open source software, or COSS).

Quartz .NET does not offer support, as discussed here, but it seems to have quite a large community as the years have passed by as well as a large collection of GitHub issues to search and use for troubleshooting.

Automatic disclaimer: I am the founder/author of Didact.

If something like paid support is a deal-breaker for your company, there are other solutions with paid offerings and support such as Hangfire (another dotnet background job library) and Didact (a dotnet job orchestrator).