I have completed Round 6 of the Wiosna 2017. Row 5 seemed too tight but this last row settled the cupping even though this ball of vintage thread broke at least three times.
Warning, do not tat with moist hands. These old threads are very dry and just a tiny bit of moislure will cause them to swell. Just wait for the thread to dry and then close the ring.
I climbed on to round 7 using a split chain and split ring, very useful techniques since I am not changing color yet. I have a plain green on the core thread S1 and a variegated green thread on shuttle 2. Currently just over 5 inches in diameter.
If you are interested in starting this doily you can find the pattern by Renata Niemczyk on her blog. She releases a new round about once a week. She also sells the entire pattern on her Etsy page.