Caped bullet kin spawn chance per floor, best odds of finding them, speed running the first 2 floors or slowly completing the last 3?

Q: Has anyone ever compiled any information regarding how often or what percent chance each floor has to spawn a caped bullet kin? And where can I find that info if it has been looked into?

I checked the wiki and many other places of information and their sources but the best I got was that they are more likely to appear / spawn the lower you go. But no more info or stats than that.

The reason I am asking (incase this would be easier to answer or to make this make sense) is I am trying to figure out if it would be faster to get the 5 caped kin I need to unlock The Bullet, if I just run the first two floors over and over since I can ace those super fast no prob, might be able to run those two floors together and reset three times, maybe lol, all in the time it takes me to finish the last 3 floors once.

Q: So would I have better chances finding them speed running the first two floors a few times or slowly pushing through the last three once?

which ever of these two is easier to answer is fine though I would really like the stats if they exist. That would be super cool.

Thanks ahead of time for any help with this!