Hi Krete, 

At the moment, Pigment does not support removing empty cells using a formula. The FILTER function can be used to filter out certain values, but it does not remove cells. The Hide empty rows and columns feature is the best way to manage the visibility of empty cells in Pigment.

As for performance, it's important to note that Pigment performs better with sparse data. Therefore, having empty cells (as opposed to filling them with zeros or other values) can actually improve performance as blank is not a value. 
 

I hope this helps ! 

​​​​​​​Please, let us know in case of any further questions!