I've been using it from the UK where it's also technically not available and it's trivial to get around. You just have to turn on a vpn to click the bet button.
You can actually get your money back at any point by selling in the market - I bailed on my Kamala bet when the results started coming in.
If you leave it to resolve it goes to the oracle which is a kind of voting mechanism https://docs.uma.xyz/protocol-overview/how-does-umas-oracle-...
Aside from gambling being iffy I'm quite impressed they've actually got the tech to work quite smoothly. There was talk of oracles and smart contracts for years and it never really worked much but this seems to be quite fast, cheap and secure.