I just learned about chamfering the tenon in this context. Setting a fillet sounds interesting. Would you say a convex or concave fillet would work best?
What an interesting problem. On pipesmokersden, I came across a hypothesis about the effect of a flat-faced tenon on laminar flow within the draft hole. The gentleman (Sasquatch) proposed beveling/funneling the end of the tenon to reduce turbulence.
It seems logically sound though I don’t have...