Very minor, not important. But a slight irritation when having to explain this function to users.
The 'Group By' button which appears on the 'Parts Only' view of an Item BOM, when hovering the mouse cursor over this button there is no tooltip describing what this is. Literally every other button has a tooltip except this one. The button still works, but it's a nuisance for when telling users which button does which job, I have to describe it via it's proximity to something else rather than the tooltip which is a standard go-to for Windows Applications.