I was just looking thru the supper high quality photos linked to above( very nice!)
Because the resolution is so high I was able to catch a possible problem. It looks like there is a fairly large ( as in 3mm) bit of thread coming of the knot of the galvo tie point closest to the laser.... you know after you tie the thread onto the galvos and then snip off the excess ... I think it should be snipped off a little closer to the knot. If that little bit of thread coming of the knot bumps into anything it will thro the galvo off.

also noticed that you have a 2 litre bottle for your top reservoir ... I have found that they can implode under the pressure of the dripper hose during a print. If this happens the drip speed will suddenly rise. You may want to re enforce the 2 litre bottle.

Looking great, Hope that saves you a bit of trouble shooting.