"Interacts" movement speed calculations?

Hey guys I dont know how to reach him so lets see if someone knows in here. I think there is an error in Interacts awesome spreadsheet. https://docs.google.com/spreadsheets/d/1sKKzRZpYv8ZQmLUWRYSmJkrUBul-07ssQr9D5770Ups/edit#gid=0

Let's have a look at Spirits movement speed for example: https://i.imgur.com/q8WuSZk.png

He calculates every speed increasing addon multiplicatively with the base speed. For example her base haunting speed is 176% and with the Mother Daughter Ring her speed becomes 246,4% which is odd imo because I think movement speed increases just add to the base speed. MDR is +40%, so 216% should be correct.

A little bit further down he talks about the amazing combo via mother daughter ring + wakizashi and how you would end up at 226% speed. But how can it be 226% ms when Wakizashi adds 10% more ms and he already claimed we would be at 246,4% with the MDR?

I think there is something wrong. Either the Wakizashi part is wrong and it should be bigger than 246% or the speed addons are calculated wrong. Billys engravings were also calculated multiplicatively.

Stay awesome! :)