hello. how much cast speed do i need if i have x2 woke cascade and 80% cdr?

https://pobb.in/gE_tWzFFgfm3 reference

https://docs.google.com/spreadsheets/d/1J-yVLmDhKqKNE8QecsPnZgNR2TDGDm41f-1tdC_BxQA/edit#gid=1230763965 when i use this spreadsheet and put 4% action speed it says i need 188% inc for regular spell cascade