Need Supports for Dowel Rod Hole?

Hi,
I am making a violin bow holder. It will snap on (I’ll probably end up gluing it) to a mic stand or tube. I have 3 holes in it, slightly angled and sized to hold a 1/4" dowel rod. Here are some pictures of my design:

The holes go into (deep-wise) about 0.3 or 0.4 inches. My plan is to put 1/4" dowel rods into them. A violin bow is a touch over 2 pounds.

QUESTION: Do you think I need support for these?

Thanks
AJ