Sadly no. I know this one and there is a couple of similar applications out there that all work pretty much the same, using a virtual uinput device to do low-level remapping of key to key. You can do macros or chords with these, but that's not what I'm after, and in any case, I prefer to do remaps and macros like that first on my QMK keyboard directly if possible, then XKb second.

Khotkey on the other hand could (among other things) remap keys per window. For example you could say that for key presses sent to Firefox (which has no built-in way to redefine hotkeys), make Ctrl-W not close the window but do this thing instead, or use these keys to move between Ctrl-f search results. These remaps would then affect Firefox and only Firefox, while with apps like the one you linked, remaps would always affect the entire system.

Another feature was freely configurable mouse gestures that can work in any application and do different things in each application.

The reason we don't have anything on wayland is that there is no generalized way for third party apps to intercept, modify, redirect or inject key events. Even global-hotkeys are still lacking in support and lackluster and complex in implementation. This is by design and there are good reasons for this, but it leaves the job of implementing this functionality (as so much on wayland) with the compositor, i.e. here Plasma, Kwin or some other module that's tightly integrated with them.