Those controllers have various modes like Xbox mode, d-input, switch mode, sdl3(new mode with Vader 5) what most people don't realize is that each mode can output different stuff and that's true with gyro deadzones too.
When you are using those controllers with gyro with settings from space station you are effectively using them in Xbox mode. In Xbox mode they do actually have a very very high deadzone, but that's not actually baked in firmware, it's baked in that particular mode. When you switch them to another mode things can be different. In Vader 4 d-input and in Vader 5 sdk3 do not have any deadzones baked in. It's just unfiltered data.
I mean purely logically speaking if there was a firmware gyro deadzone on the Vader controllers then how can steam calibrate them based on their readings? It really shouldn't be able to have any readings at all, especially when you have the controller still.
Think about it. The controller is perfectly still through calibration and steam is picking up gyro noise (which by itself means something is moving even in the slightest in there) and then uses that noise to make your gyro as sensitive as you'd like. When used through space station (Xbox mode) of course the deadzone is so high that even when you hold it and move it with small speed it still won't move. That's the deadzone people usually say it's baked in the firmware, if that was actually baked in the firmware then how can steam see all this movement even when the controller is perfectly still.
In essence what I am saying is not that those controllers don't have their fair amount of issues but a gyro deadzone in the firmware isn't one of them. As long as you are willing to use them with steam input and go through the hoops and loops needed for that you can still have a great gyro experience, more so especially on Vader 5 which somehow is way way faster than Vader 4. I can tell from being able to track comfortably on Vader 5 but on Vader 4 it always feels like I always lag behind a little bit.
Of course if you are someone who doesn't even use steam then for you it might as well be a firmware deadzone limitation.