Japanese blood grass as a red-green manure?

In a first for me, a friend has spotted Japanese blood grass being used as a cover crop in the UK.  As we do get winters colder than -5 C still (usually), this will likely not persist more than one mild winter (I hear it can be very persistent in milder climates).

This is a field in the west of the midlands of England where the soil seems badly damaged (see closeup) by flooding from the nearby River Severn over recent years.

Presumably, the root structure will help to re-aerate the soil, and there will be a decent biomass from the top growth when it dies back.

I'd love to know more from people who may have experience of Japanese blood grass as a soil restoring green manure cover?

Lots of great material on green manures in climates like England from experts such as Iain 'Tolly' Tolhurst & the late, great Dave of Darlington on the Vegan Organic Network and their Stockfree Organic Standard sites e.g.: https://veganorganic.net/2023/06/how-to-be-stockfree-organic-relay-green-manures/

Although it looks like blood grass AC, I'm not convinced that it is an obvious choice for a green manure plant in the UK.
Here's an image from suttons seeds

japanese blood grass

I couldn't find any easy sources of seed for the grass at all, and can't think that the advantages would out weigh a probable additional expense over more conventional cover crops, such as grazing rye or black oats.
I'm wondering if the stresses of the fields flooding have affected the pigmentation of a grain crop, wheat or barley, as happens with tree leaves in autumn. Just guessing here. I get red pigment on some of my fine grasses here in late summer like something awful has happened, so red pigmentation can occur in other grasses....

I agree it's not an obvious choice!

However, apparently it is used in some parts of the world (Japan?) to help against erosion damage.

Our mutual friend who took the photo is in a position to ask the land manager, so I will report back if clarification ensues.

It does look like something out of wars of the worlds!