Which is why I said: "for large financial arrangements"

Large transactions need extra special care. You need a trusted device with a trusted OS and a trusted browser, preferably with `EASE` turned on in HTTPS Everywhere so plaintext secrets can't leak out of your machine. You also need to vet the HTTPS Everywhere extension and ensure it came from the official addons site. You would also harden the OS. Using Linux is preferable over Windows 10 since Windows is targeted heavily by malware gangs.

Btw, recent versions of Firefox include an "HTTPS only" mode[1], so HTTPS Everywhere is actually unnecessary for this use case nowadays.

1: https://support.mozilla.org/en-US/kb/https-only-prefs

Huh neat. And I'm guessing enabling both would be unnecessary and glitchy? I'll uninstall the plugin now -- it has served me well.

You don’t need to do any of this if you’re using the traditional financial system. The most you need to do is make sure you don’t get tricked into wiring to the wrong address, which is a much lower bar.

I can’t send a lot of money around with any of my bank apps. It has relatively low limits.

I'm not sure that trend holds. Most banking apps let you send tens of thousands in one go. They're very aggressive with the "are you sure?" question in my experience though.

Yes mine let's me put in a limit. I have set it to a low €500 since I rarely do large purchases in webshops.

At the end of the day people are responsible for not doing business with shady stores or people. But the idea that a single QR code can empty my entire account is sobering...

Yes if you are dealing in small amounts that you wouldn't mind losing to fraudulent apps, then do it, but read my previous comment about locked down machines if dealing with very large transactions.