Sub-brow Lifts Do They Work?

I assume you are referring to a brow lift from below the eyebrows, done through eh upper eyelid crease.  This in minimally effective and in most situations of limited longevity.  A surgical brow lift (hairline) is likely going to give you the greatest longevity 

"Sub-brow" lift is not a term that surgeons use to describe the different techniques in brow lifting. A "direct" brow lift is the technique with the incision is directly above the eyebrows, usually in a preexisting crease or wrinkle. It is a good technique in an older person with very deep wrinkles and a significant brow droop.

There is an "brow lift" technique that is achieved through a well hidden eyelid crease incision. However, this does not adequately raise the eyelid, but rather stabilizes it. It can potentially give a very subtle lift, but I would not use it in someone that needs a significant brow elevation.

A pretrichial [hairline] browlift can last ten years or longer, and in my opinion is the most effective and cosmetically pleasing approach, in a person with the appropriate hairline.

   To be honest I am not sure I understand what you would like performed.  I perform at least 6 different types of brow lift/pexy procedures - coronal, pretrichial, endoscopic, temporal, direct, and internal brow pexy.  Direct brow lift in deep wrinkle patients is one option and can be performed close to the brow in a subcutaneous fashion. An internal brow pexy may be another option.  However, this prevents descent more so than produces significant lift.