Well, you don’t. But let’s think about it. The micro controller in it could easily log your keys. But logging data without retrieving it is rather useless. Either the keyboard itself has hardware to send out the data or it sends the data via your computer. The first one is absurd, what is that supposed to be, a satellite connection? The second one is not any different from having any old keylogger installed on your computer. The keyboard does the first step of collecting the keystrokes but every keyboard does that. The program does the second step of sending the data out over the internet but every keylogger does that. So could the software bundled with it be a keylogger? Sure but probably not. Making a whole company and production line with a product just to distribute a keylogger is quite overkill and risky when found out. With this line of thinking any software you install could be a keylogger, which it can be but is probably not the case. In short, there is nothing special about a keyboard that makes it more likely to be a keylogger than any other device or software. If you are somehow paranoid about this you can build your own keyboard and flash your own firmware to its micro controller. I did that but not for the reason of keyloggers, I just wanted to design and build my own keyboard.
So you use default vim bindings with dvorak? I use neovim and type in qgmlwy but I remapped the bindings in my config.