BrokenLinesDevs: Would you mind letting us know whether this works for you? We'll see what we can do from our end at the same time.
Thanks for the reply. A while back, when I had more resources to put into this sort of thing, I didn't like how antimicro works and rejected it. I don't really have the time or internet access to put much effort into this any more. However, I can adapt my own driver to swap the axes and buttons around (I didn't mention that the game also uses a fixed button mapping, because it works as long as the triggers don't act as buttons). If it works, I'll post the source in my gamesup bitbucket project (I had dropped it in favor of xboxdrv). It will take a few days, since, as I said, things are not ideal right now thanks to everything I rely on being shut down my the ongoing pointless COVID-19 panic.
I actually started on a simplified mapper and gave up on it since the game works well enough with mouse and keyboard. Changing my old driver will take less effort, probably.
edit: actually, there was another reason I gave up on the simplified mapper: the dpad (hat) control is part of the messed up axis mapping, and I don't know how to swap that with a real axis in the raw event stream. The horizontal buttons do vertical movement, and the vertical buttons do nothing. I had a sort-of-working xboxdrv mapping that made the dpad work (but still not the triggers, as far as I could tell), but the horizontal movement was broken somehow, probably due to advertised axis ranges.