Yes, turbo bags arent supposed to be kept on the turbo for prolonged periods....trapping heat inside a turbo is not good for it. Factory heat shields let the heat out after a while, whilst still keeping convection to a minimum to protect other underbonnet compomemts

SilentKilla: Have you even used a turbo bag before?

You can touch them even when the turbo is glowing red!! So, its not really an unreasonable ask..