When selecting multiple fixtures or objects by holding down shift and clicking on them one at a time I sometimes hit the wrong item which then becomes part of my selection. You can't de-select things by clicking on them again (whilst still holding shift), so you have to de-select everything and start again. This gets quite annoying and time consuming as when working in very populated plots it is quite easy to click the wrong thing.
Please enable de-selection per item in this way.