I tried submitting a post about this on a different website earlier today, but received mixed responses - it is either bloom, which I think is normal for a flapjack, or a fungal dust/mildew caused by lack of good air circulation or overall humidity. I noticed the dust maybe a week ago, but decided to look into it more today. I don't want to try wiping the dust off and see if it returns in case it's actually good for my plant. :/

Any helpful info would be greatly appreciated!

This Kalanchoe does have a coating on the leaves that protects the plant but I don't think that's the case here. Your plant has a bad case of mildew.

Is there anything I can do to start getting rid of the mildew then?

I swear by Spectracide Immunox for powdery mildew on my African violets. It is a multipurpose fungicide.

You may want to try some of that on a small portion or a leaf of your plant to see if it tolerates the Immunox.

This is an old fashioned remedy that works on my african violets for powdery mildew. I spray aerosol canned Lysol disinfectant spray very lightly on all affected leaf surfaces. It doesn't matter if it's one with fragrance or not. After a week if there's still a trace of mildew I repeat & that's usually all it takes. I've also never had a negative reaction on my plants but you may check yours since it is a different type. I find my african violets get this only in winter into early spring when we run our heating unit. It's like the warm atmosphere indoors is suitable for it. As soon as a/c is used it is no longer an issue. I hope this helps someone.

I'm not convinced it is mildew, as the plant normally can have a fair amount of farinose powder on the top-most leaves. I would not treat the plant with anything, just wait and watch. No sense in treating normality.

To my eye, the powder on this plant looks to be too much for just farinose powder but, I agree with Baja, I wouldn't do anything. Maybe next time it needs to be watered, spray the leaves with water and see what washes off.