Thanks for the suggestions guys.
Those Chrome bags look like good quality stuff. Sadly they didn't seem to have what I'm looking for.
Dakine bags all look like shit to me. I dunno how good they are, but I don't like how they look one bit.
Couldn't find that Volcom bag but I did find this:
https://www.volcom.com/mens/accessories/backpacks/substrate-d6531649Looks pretty cheap to me, so I dunno if it's good enough. 🤔
That Hex Guy bag has the same problem as many skate backpacks: you're supposed to hang the board by the upper truck, which makes the board hang low, possibly rubbing against your bike seat and generally being in the way. So far I've used snowboard bags which are designed to support the weight of a snowboard from the lower strap so can easily support a skateboard from the lower truck also. 🤔
Maybe I'll just get another snowboard backpack and patch the fabric up if it gets torn from the griptape. 🤔