Holy shit it's finally over. I'm like 95% sure that 10 is meownimum rate. After creating the input half of this solution very early on in the week, I spent a ludicrous amount of hours every day of the week trying layouts for the output half with 11r being my best up until 10 hours before the deadline. I'm sure there are probably easy ways to make the input side cheaper but I don't care right now, I'm just extremely happy that I finally got 10r!!!!!!

In theory, 9r is possible by using 2 Glyphs of Rejection (Since the main thing limiting this to 10r is the Glyph of Rejection rate), but in my experimentation it seemed like this leaves way too little room for arms/bonders/atoms.

I don't need sleep, I run on purely meowing.