Thanks for the feedback. I think better support for physical goods would be a great addition to itch.io. If you weren't already aware we added the ability to collect an address with our rewards system: https://itch.io/docs/creators/exclusive-content#how-you-can-use-rewards/selling-...
The implementation is pretty basic though and I think we can do a lot to improve how it works. Following how bandcamp approached it is probably the best approach.