Last night, while researching IE11 print problems some more, the most similar problem to mine was someone with a Brother printer who could print OK from everything but IE11, but got a mix of good and bad with IE11.
Most of the IE11 print problems see to be all or nothing, not a mix of good and bad, and my printer is a Brother.
One of the reasons I've been trying to print less is that besides having to eventually throw away the printouts, when my toner runs out I need to decide whether to buy another cartridge or buy a new printer. The less I print, the more I prolong this decision (pro-active procrastination).
Whether IE11 by itself can print is of no importance to me, but since that is what IERenderer uses, it does matter, as that is only time IE11 is used for printing.
I've already wasted more paper testing all this than I'd likely be printing this year. So, for now, if I need to print a message, I'll either view it in Firefox, or save it as text, and use my text editor to print it. And maybe when the time comes, I'll buy a more modern non-Brother printer.