Can Feliway refills be used in the Comfort Zone dispensers (and vise versa, can the Comfort Zone refills fit into the Feliway dispensers)?

The manufacturer specifically states not to use comfort zone with CEVA diffusers or vice versa. They may seem interchangeable but they are NOT. By experience I used comfort zone in a CEVA diffuser and noticed the product dispensing faster (changing every two weeks instead of 30 days), had to eventually replace the CEVA diffuser because the product from comfort zone has seeped out on the top of the burner. Not sure how this happened as the product was never turned upside down.

How long does it take to see results?

My cat is highly anxious and meows all the time. Took her to the vet. They covered her carrier in a towel with the spray on it and I bought the diffuser. I plugged it in and set the carrier down close to it and she has spent most of her time there. No more meowing. Only marked once and a very small amount when previously it was a large amount. For us the results were pretty much immediate. We have two other cats without anxiety but they have been pretty chill since plugging it in. I will be having it sent monthly!

Does it help with cats that just won’t settle down at night? Would love to be able to sleep in the same room as my 10 week old kitten

Cats ARE nocturnal, so there isn't a hormone issue here but rather a circadian rhythm disorder... As in, YOU'RE not awake during the instinctual "hunting time"! However, kittens sleep more than they are awake because growing cannot occur unless they are asleep, so you may be able to capitalize on one of those long naps with some intense rowdy play that mimics the hunting they want to do at that hour, followed by a protein rich dinner. Then, quickly get ready for bed while they're cleaning themselves after their meal, then plop them onto a super soft faux-fur blanket that's gathered into a nest shape with a heating pad underneath (not too hot!), then give them some skritches around the face a few times (mimics a mother licking them) while cooing in a soft voice, and that child will be OUT for at least 5hrs.