Hardie board tips

[Leo99]

I'm redoing a bathroom and expanding the tiled area about 6 inches to the side on one wall and 6 inches taller on all 3 walls. I need to fill in 1/4" all around and figured 1/4" handie board would be perfect. I tried to score and snap it lengthwise but it didn't snap. Should I stick to snapping it on the short side; would that work better? Thinking about switching to 1/4" drywall instead for ease of use.