Stub cells are not being styled

[GabrielNM12]

Hi! First of all, thanks for the library!
Iḿ trying to parse existing tables to excel using your library, and by using the 's' type with an empty string, excel is not recognising the cell as blank because has an 'string with length 0', which for some reason, it doesn´t consider blank.
Using the 'z' type, the styles don´t get applied, I'm, only trying to put simple borders around the cell, would you know of any alternative?