Early on, I always made my plugs from a piece of hardwood dowel spinning it in a drill chuck and shaping it with a couple of different files. Seemed like every time I had a batch of horns to ship out, I was out of or low on plugs. Found a place to buy fiddle pegs in bulk and life took a better turn for me.
So, I like fiddle pegs.
HC/PC? Probably not.
Functional? You bet.
And considering the time value of labor, much less expensive.
BUT
I am talking as a person making horns as a business, not as a hobbyist. YMMV