Basically I make them safe no matter what.
I had 1 DF shaft split at the nock while shooting in a horn bow once.About like a dry fire experience.
Many times I horn insert shoot shafts also besides split timber shafts.
Since then I wrap them even if a horn insert is put in.Horn inserts of at least 1" long.
My bandsaw cuts a nice 1/16" slot for inserts.I use smooth on for glue.
I made a hard wood slot cutter too for a single blade hack saw blade that works too.
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I think the horn inserts do help reduce wear from the serving.