The tokens would allow you to access a share of the payback on the loan, or the executed deed in the event of default confirming your interest. You are correct,

The tokens would allow you to access a share of the payback on the loan, or the executed deed in the event of default confirming your interest. You are correct, tokens are not securities. As I understand OP’s question is whether or not this is technically possible (not whether this is an actual problem worth solving). It is technically possible. You have only shown why it might be risky or undesirable.