Beautiful beads.Those holes can be improved with a bit of effort. I am a stone beadmaker and I chamfer my bead holes with diamond charged ball bits that are usually used in carving. By twisting the dampened bit into the bead hole it can be neatly ground down. A bit about 2 mm larger than the hole works well. I use a 100 grit bit and then a 600 grit bit to smooth the hole. You may not eliminate all the sharp edges of the holes due to what looks like rather unusual hole placement but you could seriously reduce the wear on the beading cord.In the past I have purchased these ball bits from Daniel Lopacki.