We moved our older daughter from RF to FF at 1 yo when we moved to her convertible. At the time the way it was recommended to tether the seat just wasn't practical without it being a three ring circus to get her in and out of her seat. It was the choice we made at the time and I'd prefer not to be judged.
I'm older and a tad wiser now with LO2. Amuse me and show me images of how you have your seat installed in your vehicle and how it's tethered or anchored. LO2 is already unhappy RF when she's alone (without the older entertaining her). And while I know it's safest, I know that I have a high distraction factor when I have a screaming kid in the backseat too. Nonetheless, I want to see if we can make this work.