IMO you should be fine now in AZ for cheatgrass. Cheatgrass softens as fall hits and the barbs become less problematic. I have areas I like to take my English Lab hiking with lots of cheatgrass, I only go to these places from October to March. U of I has done studies on eradication of cheatgrass with cows. They wait till early fall, move cows into a overrun plot and as they are able to eat the invasive plant in the fall due to the seed softening. Studies show it reappears in the spring, but at a much lower percentage, eventually being fully eradicated by year two and three of the program.
I don’t worry about much during these months, I still give my bud a thorough check but see a 95% drop in attachment to the fur during this period.
I had quite a bit of cheatgrass in my pasture when I bought my place and my cows have eliminated 90%+. 24D had no effect on it. There are a few pre emergents herbicides, but I haven’t tried them.