If e.g. the PICO is not connected with SteamVR, Visual Studio correctly leads to opening Unreal Editor.
The following messages can be found in the logs:
WaitNamedPipe SteamVR_Namespace failed because no one is listening at that name.
Starting vrserver process: C:\Program Files (x86)\Steam\steamapps\common\SteamVR\bin\win64\vrserver.exe -disablewatchdogs in C:\Program Files (x86)\Steam\steamapps\common\SteamVR
vrserver pid 31892
WaitNamedPipe SteamVR_Namespace failed because no one is listening at that name.
CSharedResourceNamespaceClient::Init(): failed connect
CSharedResourceNamespaceClient::Init(): still waiting for vrserver to reply with namespace data
Client (SteamVR_Namespace) app container state: 1
CSharedResourceNamespaceClient::Init(): received namespace data 31892
WaitNamedPipe VR_ServerPipe_31892 failed because no one is listening at that name.
Client (VR_ServerPipe_31892) app container state: 1
Received connect response VRInitError_Init_HmdNotFound. Giving up.