Highrez

XMouse v2.19.2 installed on Windows 11 Home
Mouse/Keyboard: Dell Multidevice Wireless
I'm new to X-mouse, I'd like to solve this specific problem with it:

As the title says I'd like to make my left and right wheel tilt to behave the very same way as a wheel click (middle mouse click) The reason is that the wheel click needs a much harder click then the tilt, and this makes it really uncomfortable. I used to use a Logitech mouse, where I could configure this behavior successfully in Setpoint. Here, Dell's driver is lacking in many regards, so I ended app trying your great app.

On paper this is easy. I can simply change the tilt to middle click in the app and they behave correctly if I only need a click (like for example closing a browser tab). But I work in 3D and I use my middle mouse button extensively for hold and release action (it's rotating my scene) and for this, the simple setup doesn't work.

That said I tried the advanced menu too.
"3 Press on down, release on up" - it "kind of" works but it makes everything laggy, skipping. It feels like the signal is not continuous so it's unusable.
"8 Sticky (held down until button is pressed again)" (and in the base menu "Sticky Middle Button" ): These two work in 3D! The movement is smooth, except I have to push tilt again to stop the action - same for any click event. With these they need to be done twice to execute. So close... but still far.
"9 As mouse button is pressed and when released" This sounds like it should work but does nothing for me.

At this point I run out of options. I think I need a Hold (not Click!) action which releases when I release the button. But I can't find this in XMouse.

Is there something I'm missing, or could you help me in some way?

The thing that you are missing is the concept that the tilt function does not behave like a button. A button has a discrete down (pressed) and up (released) message that happen as soon as the button is pressed and released. The tilt however, has a single message that repeats (the repeat speed varies per device) that simply says "tilt left/right".

So translating that into a button action that expects and pressed/released is a little bit tricky. There are options on the profile's options tab, particually "Ignore repeated remapped horizontal scroll" that attempt to deal with this, by waiting a certain amount of time for the next repeated tilt message, and if it not received, simulating the button up message. This is the best you can get, and the accuracy of it will depend on your actual device and how frequently it repeats the tilt message (and thus how low you can set the wait time (milliseconds) on the options tab),

That's the best you can do I'm afraid - but be sure to turn on this option, otherwise you will never get anything working with button held actions (because tilt on its own can never be held!

This is great, I ticked the option and now my "tilt wheel" puts out the character (or simulates) that I want, in my case the character tilt left "q" and tilt right "r"

Fantastic product, Microsoft should buy it from you for big bucks!