I read my bible as a Christian, so I know what it says. However I'm not immersed in the culture as it actually played out in practice.

From a reading of the law there seems to be nothing, but I suspect there is something I'm missing. I'm not sure if there is something about who/how you can ask for a loan (thus meaning such a loan couldn't be requested just anytime), or if the culture allowed you to refuse to make big loans then even though the law said you couldn't.

And what Jesus said was "Do not hold back from him who would borrow from you". The point of that may well have been the jubilee.

Realistically you wouldn't.