With this latest update the performance of the game has been improved. When pause button was added for local save some time ago this seems to have caused some performance drop which I thought I had already solved, but at least now it should be fixed.
Recently the game was also updated so that when you play the game for the first time hotkeys 1-9 are prebound to keyboard number 1-9 respectively. Before you needed to manually set a keybind before the hotkey could be used at all.