I did it like this: I just chose my next system from the list of nearby systems and noted its number somewhere, to compare with the numbers of the nearby systems in the same boxel. The last point is easier to do in a more sparse boxel (I did that in a boxel with ~90 stars, in the core regions it would be a pain in the Asp...).
And I used a colour code in my notes: Red for "Stars only", blue for systems with ELW, Orange for systems with AW/WW, Green for systems with what I search for in that boxel (in that case, HRGGs).