When can we expect a .NET Core 3.0 version of your SDK now that Microsoft has released it with support for WPF and Winforms?

Unfortunately, we have not planned it at current time yet.

Is there any progression in this case. What I mean is it ever going to be possible to use .Net Core /.Net5?

Milestone are considering introducing support for .NET Standard in the MIP SDK, but unfortunately we cannot say at this time when/if this will happen.