Ignoring that, it's nuts that the best practice is "send a little money, and see if it works". Apparently they don't even have a working transaction simulator that just runs the relevant logic on your laptop so you can see what it will do.
That's what I did the first time I did a bank transfer between two of my banks accounts. Maybe that's just me being paranoid but when sending money I like to test it first.
This passes the "does it sound like email?, it might be decentralized!" smell test, anyway.
I haven‘t tried it, because I don‘t do much crypto stuff at all, but I thought this specific functionality, to dry-run any scenario, from any account, was very intriguing.
We need to re-write this in Rust before there can be universal acceptance!
several of these projects will set up a local chain with presets to test exactly this. probably worth doing before sending large amounts to random contracts.
The contract is going to be at a different address, all the accounts involved are entirely different, the state of the contract is different. Even proving a contract at one address is the same as the contract at another address is non-trivial.
Pretending the existence of a test net proves anything is a lot like pretending the availability of source for your OS, compiler and dependency stack proves something. Maybe possibly for a professional with unlimited time, but that's it.