In a clean environment configured in 4.0.5 I used VNC for hosted engine VM console during setup.

In web admin gui I see that the graphics protocol for the Hosted Engine VM is indeed VNC and Video Type VGA.

I have verified that if I configure a VM with VNC graphics (video type both cirrus and vga tried) I'm able to connect to it with remote-viewer from Linux client and with virt-viewer in a W2012 client.

A part from the usual command 

 hosted-engine --add-console-password

and related vmcviewer one from console, can I connect  to the VNC engine console also from web admin gui? 

Both from Windows and Linux I get error

Unable to connect to the graphic server C:\Users\Admini~1\Appdata\Local\Temp\console-12.vv

Unable to connect to the graphic server /tmp/mozilla_g.cecchi0/console.vv

Can I setup console to spice after install? And in case can I connect to its console from webadmin gui then?

Thanks,

Gianluca