My R. imatator Chatzuta lay infertile eggs in the film canister just like an obligate. Perhaps that's whats going on with your Ranitomeya. When the female is laying she's pretty much submerged in the cannister water. I've seen it a couple of times. No one told them that was another Genus, I find trees and mushrooms don't seem to read the books and papers we write about them either.
My benedicta are just Spazzes, sounds like yours are too! Mine hang out in the water pools in the big bromeliad every morning. I definitely have special protocols for misting and feeding them. When they startle it's chaos, so I try to keep them calm and be very un intrusive.
Ravage: yes she did that also when ”nursing tadpole” with male. I remember her doing that sometimes also without tadpoles. Good to know it is specifically egg feeding happening when diving. Parents in my viv spend often time with their babies female submerged or not. In the picture one of the babies