Nothing wrong with wanting to stick to X11, but if you are doing so because you want to avoid bloat, you are probably confused.

Here's a fun example I had to work around: move your mouse outside a window, then back in, then scroll the mouse wheel one tick, and repeat. On apps handling fractional scrolling you'll never end up scrolling anywhere - this is because.. X11/Xinput gives the cumulative distance scrolled anywhere, and so apps use the first scroll event on mouse entry to "calibrate" the current position to then be able to calculate a proper delta.