Now go ahead and change the bitcoin price from sub $400 to $500 and the difficulty increase to 5%. Oh look, Tubes break after after 34 days. Cool!
Good luck with the 5% difficulty increase.
Good luck with pretending that any fixed percentage difficulty increase is realistic. Also, with bitcoin prices so low, small difficulty increases are more likely than large ones.
Edit: The last 10 difficulty increases with oldest first are as follows:
18.10%
12.44%
14.51%
24.93%
3.08%
8.08%
5.30%
20.86%
15.03%
8.75%
The next difficulty increase is looking to be around 9.3% at the moment.