If you look at some of the more scientific approaches to testing of the MVP, you'll find that it never fires above 5V or 11W, regardless of how you have it set.
Say, for example, you're using an Aspire Nautilus Mini with a 1.8 Ohm BVC head.
So, you set your MVP to fire it at 5V. It will never actually make it to 5V, it won't fire above 4.4V, because firing above that would be in excess of the 11W limit.
On the flip side, say you're running a 3 Ohm single coil Boge Cartomizer...
You set your MVP to fire at 11W. It never truly achieves 11W set like this, because that will require 5.7V, and it can't fire above 5V. So you're actually getting 8.3W instead of the 11 on the display.
Even though you set it to something that should not be achievable, it will still fire and limits itself without letting you know... It's deceiving in a way, because you THINK it's firing at what you have it set to, but that's just not the case.
If you check out the video linked above at around the 13 minute mark he starts looking at the numbers... You can see pretty clearly that the device never reaches the set numbers... Effectively, it never fires below 3.3V or above 5V, and never above 11W.
The MVP is a great device, don't get me wrong, but it doesn't always tell the truth!