The VB approach does leave my down remarkably dry in comparison to without. The main spot I do get my TQ damp is right by my face from my breath. My workaround for that has not been exciting as Shug's approach with a bib suspended from the ridgeline, but it does help. I take a remnant of IX and fold it over the end of my TQ. That keeps the condensation from my breath on a waterproof piece of material. If it gets frost on it from my breath, I just shake it off. It also adds a wee bit more warmth to my torso.
If you're just out for a night or two, getting your insulation damp from insensible perspiration isn't a show stopper, but it does result in progressively less insulation benefit. Longer outing would have greater consequences unless your in a position to accomplish some field drying.
Most insulating sleep gear has some form of DWR that prevents actual dew and mist from soaking into the down. On the other hand, the insensible perspiration is often realized more in the form of vapor. If the dew point is in the wrong place, that trapped moisture will freeze inside our quilt. A slightly compromised piece of down gear will dry surprisingly well with a bit of sun and wind.-more so than most would expect. However down that has been more heavily compromised with moisture can take hours in a dryer to resolve which despite many comments on the weight of my pack I do not carry.