Not What I Had Hoped For
Lidpicker, you've asked, so I am going to answer.
1) I specifically indicated interest in modular helmets. All websites have those as a category on their own when searching. Why not show them as their own category on your report? They are very different than closed faced helmets.
2) There are only 21 modular helmets listed. Many aren't even current, and many current ones aren't listed. BELL SRT Modular. AGV Sportmodular. HJC RPHA 90S and 90S Carbon to name a few.
3) I think you've got a great idea, But it needs work. Categorize modular's on their own and expand the list significantly to include current helmets. I also wonder if adding in a measure from the top of the head to the jawline would make sense. i.e. how tall is the head. I purchased an AGV Sportmodular and had to return it because, while it fit my head great from a circumference standpoint, the bottom of the helmet squeezed my jaw to the point of making it throb after 10-15 minutes. If the helmet was a 1/4" deeper or my head a 1/4" shorter, it would have been perfect.