The 150/14 wind may give an instantaneous tailwind of 5 kts, but in my experience, this wind is usually flicking between 120 and 180, giving tailwind even above 10 kts on Rwy 27 at times. The quoted wind (150/14) is an average, the tailwind component that precludes a Runway being nominated is the maximum not the average.
It sounds like a case of information overload. I suspect the people who set the tailwind limitations don't have this type of data resolution in mind.
My experience on warm-hot days with a light and variable wind is that the windsock isn't a reliable indication of the actual wind at any one time, it is just as likely pointing to the nearest thermal. The average over a period of time, and an awareness of the forecast wind is a better indicator.
I'm not a jet pilot, but I suspect they can handle a bit of windshear from thermals without difficulty, and you probably don't want to close a runway just because a thermal keeps popping off upwind of your anemometer.
Stronger winds of course are less affected by thermals - but this thread seems to be mostly referring to light wind days.
Today at times the wind was 340/8 at the northern end, 160/15 at the southern end and anyway in between at other points on the field.
Sounds like a classic case of effectively measuring vertical air movement, not horizontal.