Multi Root Workspaces not supported

[NCC1701M]

Environment data

dotnet --info output:
.NET-Befehlszeilentools (2.0.0)

Product Information:
Version: 2.0.0
Commit SHA-1 hash: cdcd1928c9

Runtime Environment:
OS Name: Windows
OS Version: 6.1.7601
OS Platform: Windows
RID: win7-x64
Base Path: C:\Program Files\dotnet\sdk\2.0.0\

Microsoft .NET Core Shared Framework Host

Version : 2.0.0
Build : e8b8861ac7faf042c87a5c2f9f2d04c98b69f28d

VS Code version: 1.17.0-insider
C# Extension version: 1.12.1

Steps to reproduce

Run the following commands

mkdir XPlatform
cd .\XPlatform
mkdir XPlatform.Shared
dotnet new web -n XPlatform.Server
tns create XPlatform.Mobile --ng --appid com.ejot.XPlatform
ng new XPlatform.Web

Then create a code workspace file (XPlatform.code-workspace) with the fpllowing content:

{
  "folders": [
    {
      "path": "XPlatform.Mobile"
    },
    {
      "path": "XPlatform.Server"
    },
    {
      "path": "XPlatform.Shared"
    },
    {
      "path": "XPlatform.Web"
    }
  ],
  "settings": {}
}

Open VSCode Insider.

Expected behavior

Omnisharp-vscode should detect that there is a c# project in XPlatform.Server and provide intellisense for .cs files in this folder.

Actual behavior

Omnisharp still shows the Running state

When I click on "Running" it only let me select the project XPlatform.Mobile

The Omnisharp log shows the following output:

Starting OmniSharp server at 2017-9-20 09:18:10
    Target: C:\VSCode\XPlatform\XPlatform.Mobile

OmniSharp server started
    Path: C:\Users\<<user>>\.vscode-insiders\extensions\ms-vscode.csharp-1.12.1\.omnisharp\OmniSharp.exe
    PID: 9460

OmniSharp: -s C:\VSCode\XPlatform\XPlatform.Mobile --hostPID 8552 --stdio DotNet:enablePackageRestore=false --encoding utf-8 --loglevel information formattingOptions:useTabs=false formattingOptions:tabSize=4 formattingOptions:indentationSize=4
[info]: OmniSharp.Startup
        Omnisharp server running using Stdio at location 'C:\VSCode\XPlatform\XPlatform.Mobile' on host 8552.
[info]: OmniSharp.DotNet.DotNetProjectSystem
        Initializing in C:\VSCode\XPlatform\XPlatform.Mobile
[info]: OmniSharp.DotNet.DotNetProjectSystem
        Auto package restore: False
[info]: OmniSharp.DotNet.DotNetProjectSystem
        Update workspace context
[info]: OmniSharp.DotNet.DotNetProjectSystem
        Resolving projects references
[info]: OmniSharp.MSBuild.MSBuildProjectSystem
        Omnisharp will use local MSBuild.
    MSBUILD_EXE_PATH: C:\Users\<<user>>\.vscode-insiders\extensions\ms-vscode.csharp-1.12.1\.omnisharp\msbuild\MSBuild.exe
    MSBuildExtensionsPath: C:\Users\<<user>>\.vscode-insiders\extensions\ms-vscode.csharp-1.12.1\.omnisharp\msbuild

[info]: OmniSharp.MSBuild.MSBuildProjectSystem
        No solution files found in 'C:\VSCode\XPlatform\XPlatform.Mobile'
[info]: OmniSharp.Script.ScriptProjectSystem
        Detecting CSX files in 'C:\VSCode\XPlatform\XPlatform.Mobile'.
[info]: OmniSharp.Script.ScriptProjectSystem
        Could not find any CSX files
[info]: OmniSharp.Services.WorkspaceHelper
        Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.CSharpWorkspaceOptionsProvider
[info]: OmniSharp.Startup
        Configuration finished.

[DustinCampbell]

We're planning on adding support to OmniSharp here: OmniSharp/omnisharp-roslyn#909. I'll keep this to track the updates that will be needed to C# for VS Code.

[Jonatthu]

@DustinCampbell

Looks like this is still happening on 1.16.1

[AlseinX]

On the last few days of Year 2019, this problem still happens.
Switching among multiple VS Code instances is still needed for multiple solutions.
This issue has been lasting for over 2 years without being solved.
It there any technical problem that prevents implementing this or this commonly requested feature is placed on very low priority?