Deed must list the wallet address, like a property description. That's the only way.
Really? Will municipalities accept a wallet address? Highly unlikely.
Which countries does Swarm Fund plan to operate in? Can they prove that each of these countries will accept a crypto wallet address on a land title deed? Highly unlikely.
Let's say that these municipalities will, which is a stretch, how does Swarm Fund prove that my ERC20 token owns a percentage of the assets that their wallet owns?
I'm not saying it's likely or that it's going to happen realistically, but I know that if you need to write the deed, things can be added in there. Although I agree the likelihood of anyone knowing exactly how to even get started would be a stretch. But not impossible.
Forgot to add the other part of you question. They can only prove that the wallet owns the property. Not the token themselves. Just like anything else on the deed it says "Value exchanged for deed" tokens are simply a medium of exchange. Again, not likely, but not impossible.