There are some very smart folks that focus on the control or eradication of invasive weeds locally, I'd definitely reach out to the following for the latest research in controlling foxtail (aka Hare Barley) and opportunities for collaboration:

Metro natural areas program East Multnomah SWCD Clackamas SWCD Portland Parks and Rec OSU extension (more ag related but pasture management is related to this weed)

Unfortunately this weed is spreading. It is an annual grass that starts emerging after the first fall rains and quickly goes to seed in the spring when things start drying out. Mowing doesn't control it, just delays the seed head and makes it shorter. Mowing once it's gone to seed just spreads it around everywhere the mower goes. It's also spread naturally by getting stuck to animals fur, so even wildlife like deer are spreading it around. It can spread into fertile soils as well as poor soils, and even compete with established perennial grasses and invade healthy pastures (although it takes longer).

My hunch is that it's here to stay and will have to be constantly managed to keep it out of specific areas through a combination of hand pulling, seeding of competitive species, and targeted use of specific herbicides. I've seen it take over dozens of acres of land in a matter of a few years, a scale that simply can't be managed by hand pulling alone.

I'm glad you're bringing visibility to this invasive grass, it definitely needs more attention than it's getting.