Let's say you did 1200 per hour, to be conservative. That would mean 44 trips/hour. Therefore, one trip would take 82 seconds. I just timed banking/running back and forth, and it takes 18 seconds: withdrawing 13 of one item, 13 of another, running to forge, running to bank, banking all. So crafting 27 bracelets takes 64 seconds; crafting 13 would take about 32, I presume. Crafting and banking would then take 50 seconds. I think I could craft 900-950 gemmed bracelets per hour.