For what it's worth, I have a specific Brain in which I link items between a dozen or so classifications. Items from a specific classification belong to a certain thought type. Apart from a home thought, I set all the classification thought types as a pin. Works very handy and fast for me.
By the way, in Windows 10 pins are graphically surrounded by a sharp and nice colored box. In iOS the box is made up of a dotted line which a bit poor in comparison to the Win 10 version.