Most failures in this industry are at the terminations. The manufacturers are aware of this. They are not planning on designing termination to the 90C column for that reason.
You posted just what I was going to say. You use the 90 deg column all the time. Every time the wires get bundled, go through an attic, or in a boiler room. You need the higher amperage to start with so that by the time you need to derate the wire, you can be right back down at the proper amperage where you need to be.
