I agree about the stationary circle. It seems a bit too small.
My room scale boundary is saving just fine, however. Even if I put the headset on while outside the boundary, it seems to still know where it is. I never had to redraw it.... until I went and got a swivel chair and set it in the middle of the space. As soon as the chair was added, I had to redraw the space. So, I speculate that any change to your play area will trigger a redraw. Changes in lighting might have the same effect.
I bought superhot in 2017 for my rift. Shouldn't it show free in the quest store guys? Robo is showing free in quest store, I assumed because I had it on the rift too?