You don't use the 1/2" X 1/2" screen BG supplies on the hopper?Used to be double 1", now replaced by 1.25". Much better setup for sure! I had one 1.25" partially block this spring (stuff still came out when I checked but those 2 rows are yellow???) Apart from that one time in 2 years I have had no plugging issues. There always seems to be some little lumps in urea.
I do use that screen and it works wonderfully except if you don't have it centered or crowd it the product can run over the edge of it.You don't use the 1/2" X 1/2" screen BG supplies on the hopper?
Some little lumps you say!
That crap they extort for these days will sometimes have 1/2 a shovelful of lumps on a 15 T fill!
I never plugged any lines due to lumps and the fertilizer would have been unusable without that screen.