We are also interested in this, it would be good to know when VS 2019 is out there's no barriers with migrating over. We use Resharper and Ghostdoc heavily and Resharper already has support for 2019 RC. I think it's important there's early visibility of Ghostdoc in major VS updates at least in the RC and day 1 support for the final.
I'm a .NET Dev Director building Episerver solutions on the cloud using VS, Resharper and Ghostdoc