Makrut, as far a Romeo fertilizer, Four Winds has been selling that fertilizer for a long time. I believe it only comes in a small bag. I would think the urea quality would be OK. Myself I have never used it as I do not like the 24-14-14 ratio for containerized trees. - Millet

Well,
urea was and is still a problem in fertilizers, because urea is cheap!
But urea seems to correspondent with temperature. I guess plants in cool places will react much more tender to Biuret than during the summer.
So my plants didn't show any sign of biuret toxidicy during the summer, but in fall and in winter I quickly got symptomes, and those remain on the tree.

So I switched to a urea free fertilizer... to get rid of those symptomes.