ganu81 If I were to invest in Blazor it would most very likely not be until .NET Core 3 stabilizes enough to warrant spending time on it (RTM is planned soon though).
The new version of SmartAdmin 4.0 has been adapted primarily for .NET Core 2.1 and 2.2 and uses a combination of RazorPages and MVC pages so that has my current focus. Once my timetables improve I will take another stab at looking to adopt the Theme for Blazor, but currently I am awaiting MS on deciding their direction and intent with Blazor as I rather not fall into the early adoption trap again.
Hope this helps,