Also im not sure whether the scolling problem is actually tmux fault. Tmux uses the alternate screen buffer, the alternate screen buffer is activated using the smcup/rmcup terminfo capabilities, whose semantics actually say that it "fixes" the window viewport in-place so absolute cursor movement has a known zero position. In this state, any native scrolling attempt should have no effect, and the keypress/scroll wheel events should be forwarded to tmux directly.
For some reason, every other terminal emulator still allows local scrolling in the alternate screen, which kinda breaks the semantics of smcup/rmcup and easy scrolling in tmux, too.