In that case, it makes perfect sense! :)) my comment was from the accessibility perspective, that more people will know how to adjust report/list filters than to script something.

To practice and master your scripting, i recommend you to focus on the variable naming convention, instead of var gr to go with var incidentGR or something like this.

And also some consistency, in the last one you have GR (glideRecord) and GA (glideAggregate), instead try something like var attachmentGR = new GlideRecord('sys_attachment'); it can make your code more/better readable when there will be more lines or more separated functions or conditions.

Keep going and thanks for sharing!