I only say that because wooden boards now feel hollow to me when I handle them. Do you have a large wooden board you can weigh?

Let me weigh my largest wooden one, it shows 1.928 kg, so less than my hisoft. Amazon link with dimensions: Midori Way Thick Bamboo Wood Cutting Board with Juice Grooves - Extra Large 18x12 inches https://smile.amazon.com/dp/B010A5JP5K

Visually, it looks like same thickness and roughly the same surface area (wider but shorter) than hisoft.

So without doing the full math above it does appear at first glance to be denser than bamboo.