In KDE, YOU ABSOLUTELY CAN slam the mouse and click on below the bar and it still work the way you need. Same goes to close window button on fullscreen. You can slam mouse into top right corner. I can't live without theese simple features.

Also you defenitrly need to try floating on kde. When there is some window going to touch the panel, it retracts and stick to the side without floating(same behaviour on window maximize). So you don't waste any space by turning on floating. Also the smooth animation is cool.

Edit: Here is what I mean