My bad, it does use 365.25. I’ll correct it on the blog, as 365.25 is calendar-based, while 365.2425 is more accurate scientifically, but actually less-so if you annualize.
I just checked the code, and I’ve fixed all annualized metrics apart from ROI and TWR 
By the way, IRR was always correct in this regard.
I’ve just pushed a new version 1.36.3 - it shows 59.05% for annualized ROI.
Juggling all these numbers and complexity may be sometimes confusing. Many thanks for being patient and sharing the test case 