Well, it's taken me weeks to think of a new absurd question but here I am at last. You're welcome!
I'm looking at using a small, adjustable, switching buck regulator (likely a LM2574) for a very basic supply:
120V AC in --> stepdown transformer --> bridge rectifier --> switching regulator.
This will be used in a commercial product. I've amazingly not designed with one of these before. While I don't think for this product we need to technically be concerned about EMI, I'm curious if a little bitty switching regulator like this generates all that much noise? I'd rather not add cost with upstream filtering if it's not needed.