Needs support for empty variables

It would be helpful to be able to keep empty variables like “” or especially 0. Sometimes you want to use a 0 and keep the variable available so that it can be adjusted in the future. I use global variables as coefficients in formulas that sometimes need to be adjusted by non-technical users, which this plugin is great for, but currently setting the value to an empty string or a 0 results in the variable being completely deleted.