There are a bunch of threads on the topic… You'll have to sift through here: https://www.backyardchickens.com/newsearch?search=brinsea+humidity+pump
On the Cemani, that is a controversial breed to say the least. There are a few threads on them here, as well as breeders and owners that can give...
There is a new Brinsea model that comes with a humidity pump, so it basically does everything for you. @Yorkshire coop has one I believe. The model I used required nothing more from me than filling the water reservoirs now and then and take it off the automatic turner when the eggs were ready...
I had a Brinsea 20 ECO incubator and I loved it. They're not cheap, but they are worth the price tag. Hands off, holds temperature and humidity well. There are some more reviews on them and a few other makes and models here:
https://www.backyardchickens.com/products/category/egg-incubators