Thank you Mark for your write up on an issue that plagues a lot of LCD owners out there. Being a "tinkerer" and "what if" person myself I appreciate the out-of-the-box thinking... something for me to file away in the back of my mind.
Naysayers will be naysayers. If the solution doesn't work for you, for whatever reason, then don't do it. If your solution increases the chance of component failure, fire, earthquake, or mass extinction then I might understand the negativity.
Bias lighting worked for me but I realize it doesn't work for everyone as it's dependent on screen to wall distance, wall color, expense, etc, etc. It didn't get rid of the light bleed of course but it "hides" it from my eyes.
Yes, proper calibration helps too but "proper" calibration, however one defines it, is out of the realm for many owners because of expense or experience. Even then it may not eliminate the light bleed.
It's all about making do with what you already have or have access to. It would be far more productive to hear from folks who have tried your idea or who have a slightly different take on it. There's one undeniable fact. For 2.40:1 programming, your solution hides light bleed in a darkened room.