No, you can't: All upgraded Windows 10 installs have exactly the same key.

It's the fork developed by the original author. He transfered the main repository to another contributor for maintaining and then open-source drama ensued.

I don't think they've diverged enough to recommend one over the other. I'm using Origin.

i think the original author doesn't want to take such big responsibility. it's a hobby for him only. he only works on it for fun so he transfer to another, forked it and add features as he sees fit.

Then your giving all your online banking login data to SOFORT AG and/or Klarna AB. To me that's even worse.

I like giropay since then I'm only dealing with my own bank.

Yes, you are right, SOFORTÜBERWEISUNG is not perfect.

If I had the choice, I'd pay with a Lastschrift.

You can add external POP accounts, and I think that would be the solution for OPs problem.

Protect yourself by only using apt-get and packaging open source software yourself if isn't already packaged.