HP-15C missing feature

[naddy]

I can already hear the rustling of the pitchforks, but there is a small feature I wish the HP-15C had, but it unfortunately doesn't:

An annunciator in complex mode that signals whether the imaginary component of the X register is zero or not. Let's say a small i.

Heck, with that you could leave the calculator in complex mode the whole time. "Oh, an imaginary part popped up, I better check what it says."