???
What do you mean exactly 4L3X ?
If you mean runway expansion i.e. the additional short runway? well I'm not sure how valuable it would be to Birmingham.
If you mean the runway extension, it's a no brainer. Of course the airport needs its extension, it needed it years ago. It also makes sense from an environmental perspective, larger more modern aircarft with larger payloads full of passengers who would not need to leave their carbon footprints (ugh) all along the M42 / M40 / M25 / M23 / M6 etc etc etc.