Been using RU for many years. Yup, it clogs the screen if you leave it in the sprayer too long. Spent a few hours troubleshooting that problem so it stuck in my brain (what's left of it).
I have problems with it gelling too. I think it's the water ph or solids that contribute to it, so I don't store mixed RU anymore.
I also get gelling in my larger sprayer tip screens no matter how many times I rinse, so now I remove all tips and thoroughly wash/rise/dry them for storage after use. That's probably what I should have been doing all along anyway, and it sure saves time the next time I need to spray.
JD 770, Yanmar 180D, JD 420 (not running), had a Kubota B6200
No problems here. Our water has a very low pH and no minerals. Probably haven't left it in the sprayer more than about 6 weeks, but I have been using RU for over 20 years.