Better than that idea, you don't even need an additional stand. The ASK (the 9.7" one that you say you are keeping) can be folded around back to provide a more upright stand position, and you could use that with the regular Apple magic keyboard.
In regards to this discussion, I went to the Apple Store today and bought the ASK for my 12.9" iPad Pro. While I was there, I did take a look at both the 9.7" iPad Pro and the 9.7" ASK. While the keyboard is smaller, I do think if that was what I was typing on regularly, I would get used to it. Most of the keys are decent size, and only the keys along the left side (Tab, Shift, etc) are significantly smaller.