Trying to rank the last few levels of refine with R1 prod mastery is going to be frustrating. You need fails, so you will need as many -dex enchants as you can possibly get. I had <100 dex, never let my prod mastery get above C, and it was still a pain. You need those fails. 4 of 5 star Red Sunrises also help, with their -10 dex modifier; and the current chest event drops a crapload of them. Getting the Master title is actually easier than completing R2, since you no longer need fails. I'm about 2/3rds of the way to Master, having completed everything but Iron and Copper.
they only have r1 production on their metallurgy alt. they're fine as far as that goes. :V