From what I've been able to find, configuration can only be done via the Launcher as there is no way to create a "configuration" file from the Launcher, nor can you actually even open the Launcher's main screen without connecting the device you wish to configure.
The reason for the animosity from me is the very real experience just this past weekend of receiving my hardware, just to find the Launcher was down all day Saturday because the entire Launcher was down because they had one backend endpoint that fires during device connection to the launcher and it was 502 Bad Gateway all day Saturday.
I reached out to support on Saturday and still have not received any response.
As for one-time configuration and not needing it again - I think that fully misses the point of having "easily" configurable hardware. If I wanted to just set it and forget it, I'd just buy a $25 Dell keyboard and call it a day. A $100+ peripheral should NOT have this kind of limitation. Myself, I can't forsee all the mappings and macros I will ever need so I don't have the ability to configure it one time and never touch it again, though I'd love the ability to do so, it's just not realistic nor what I was paying for.