I have fixed ctrl+a to ctrl+z on linux and mousewheels on windows (all meta bits are now set on all OS). Please check and report if we can close.
Note 1: If we want, we can also generate mousewheels events on windows (instead of arrow key+meta bits events), I opened a branch for that. But trackpads may generate way too many small deltas that overwhelm the image side event loop, so not sure it is ready.
Note 2: for exotic ctrl+key, I'm afraid that it will be difficult to obtain consistent behavior cross-OS cross-keyboard...