I took the liberty of testing it myself. You can use the keyboard, the dock and power the dock/phone all at the same time. I tried turning on the keyboard battery while delivering power to the phone via the USB-C dock and the keyboard battery would not turn on, which is a good thing.
I'm adding a new reply and not editing my last post so that this thread will get bumped (maybe, it might append to my last post anyways I'm not sure how the forum software works) and people who want to know can know that it's safe to deliver power to the phone via the USB-C dock while using the keyboard because the keyboard battery will not allow itself to turn on, so it's not possible (at least from my testing) to accidentally allow double charging and possibly damage the phone.
Disclaimer: I am not an expert, I'm not recommending you try this on your phone LOL.
I'm adding a new reply and not editing my last post so that this thread will get bumped (maybe, it might append to my last post anyways I'm not sure how the forum software works) and people who want to know can know that it's safe to deliver power to the phone via the USB-C dock while using the keyboard because the keyboard battery will not allow itself to turn on, so it's not possible (at least from my testing) to accidentally allow double charging and possibly damage the phone.
Disclaimer: I am not an expert, I'm not recommending you try this on your phone LOL.