I don't really have any suggestions

I nap all mine in the same room and all I do is place them in playpen/cot, cover them up, say goodnight, turn on white noise machine and leave. They are sleeping by the time I get upstairs and turn the monitor on!! However...the youngest (19 month-ish) will sometimes wake up 30-60 minutes before the rest of them. She too is a singer and a chatter!! I speak over the monitor and tell her to lie down. She usually listens but I can still hear her chatting sometimes lol. She will usually fall back asleep. If she doesn't and it's getting too disruptive for the others, I go get her.

It's only occasional with her but in the past if I've had a noisy napper, I put them in a playpen in my dc kitchen. I have to keep the playpen in my adjoining laundry room which is kinda in the way but I'd rather do this than have their naps disrupted.