We have a very shallow wooden gutter built onto the addition of our home.

I recently cleaned them out and tested the downspout with a hose. That's when I noticed dripping water from a hole. I thought I would patch it somehow until I noticed a whole bunch of holes throughout the gutter (maybe a little bigger than 3/8 each).

I am pretty sure the previous owner intentionally drilled these to help dissipate the water during heavy rain (a couple of the window sills have some clear water damage).

Most of the holes are clogged with debris (maybe even roofing tar).

Do you think these holes were intentionally drilled? If so, is this a bad idea? Or is it ok and should I make sure water can flow through them?

Thanks for any feedback.