Why not let people try it from abroad? Not in the USA? No luck.
Why does the withdrawal rate need to be a multiple of 0.5%?
It's curious that the highest chance was associated with the highest (100%) stock ratio.
What's genuinely missing for you is NZ tax and NZ Super. So it worked, but you got the generic version.
On the existing calculators, they're good and I use them too. Most are tried and true against US history, which is the one sample where equities did unusually well. That's the gap I was after.
The reason is that GDPR has extraterritorial reach and real penalties, and doing it properly is weeks of work I haven't done for a market I'm not launching in yet. I'd rather block the signup than pretend I'm compliant. Not a satisfying answer if you're the one blocked, I know.
The 0.5% step is because the Quick Check is a 66 cell precomputed grid shipped to your browser, so it runs with no account and no server. The builder takes dollar amounts. On residence, there's an "other, rest of world" mode that runs an untaxed gross projection, so it isn't US only.
The 100% stocks result holds up. In the international panel, bonds get wrecked by inflation more often than equities do, so more stocks wins on "did the money last" while being much rougher along the way. Cederburg and co-authors find the same. That's why the full detailed results show the full distribution and the drawdowns, not one number.