Thanks again for all your input. After the first full night with it running like this, I woke up to 78* upstairs and 77* in the basement
It used to go 78* in basement, 71* upstairs. I moved the boot so it lets a little more heat stay in the basement. It's warm out again today, so I'll have to wait until it gets cold to really see the effects.
I've grown sort of fond of the flex pipe and C-clamps. It's not like I have dinner parties down there. My kids just trash the room with their toys. And they think it looks neat. Very Frankenstein.