If you speculate, you need to be ready for such massive swings. I just drip buy/sell as the market goes down/up.

Why not make 2FA opt-out? This would work for most cases or am I missing something?

No you are not missing anything in my opinion.

The reason this is not offered (IMHO) is that a lot the use (on the users side) of 2FA is from people that want better security, while a lot of the push (on the developer side) for 2FA is from people that would like to see the use of passwords almost disappear.

I have been using this for around a year and it has been great. I've been upgrading it regularly and so far nothing broke. I use a local self hosted mysql dB.

I did make 1 small change- ad block was blocking the upload being called and I renamed the api so that ublock does not block it anymore :)