It happens way too often. I can't break decades of muscle memory of ctrl+W closing the current tab (event sheet or layout in C3's case). Then it takes another half an hour (no exaggeration) to open the large project again, with nothing for me to do while I wait (other than writing yet another angry post about it here to help pass the time), losing precious time in my already tight schedule, because C3 doesn't even bother to keep the project in RAM/memory so that I can at least open it faster after the fall. If only I had a software that can disable the combination of ctrl+W doing anything as a work-around. I only need C3 for exporting C2 projects, but during that time I also need to use it for ~a month of last-minute work to make improvements and fixes for the platform I'm putting it on. I wish that after years of C3 being out, an exit confirmation option was already put into it, instead of my asking for it multiple times.
Also, C3 doesn't bother to save how we left each layout before, even after saving, even though C2 knows to do that, so every time we reopen the project, each time we open a layout again, we once again have to quickly zoom out yet again, center it yet again, hide layers that are supposed to be hidden yet again, lock layers that are supposed to stay locked yet again, etc. By now, C3 should get these productivity-killing problems fixed.