It’s sterile so it doesn’t spread. Which means you can let the flowers run to seed (better for the pollinators) and not have to spend time controlling it.
Can confirm that root free/runner free nettles
do make a nutritious 'tea' for plants.
Also, ends up disturbingly smelly when you try to get rid of the
immersed, blackened stems.
Probably less of a problem on an allotment,
than along a suburban street.
Why is bocking 14 so much better? I’ve seen green manure vids on yt that suggest nettle and wild comfrey just as good...