Extremely simple

Done

what is the Hursky #1 rule of sudoku?

go

unavoidable rectangles worked this time perfectly!

Hurshy's #1 Rule of Sudoku: sudoku must always be done on a clear head.

is unavoidable rectangles just another term for unique rectangles?

Go

Done with greens

go

done

Done.

hurshy - my mistake, it's "avoidable rectangle", related but different http://www.acrystalman.com/sudoku/cet/cet-ar1\n.htm

start

done, first guess