When clicking on the spinbox it won't get the focus and thus it's not possible to override the content with the keyboard.
The user has to actively press the Tab button in order to set the focus to the spinbox before he can override the content.
This is a very annoying behaviour and it's a regression caused by dda3141d1
- At the moment using e.g. the thickness dialog and change from the default "1.0" to e.g. "21.3" triggers 4 recomputes. This takes a lot of time and is unnecessary. Qt offers therefore to disable keyboardTracking (and we use it already in the TechDraw workbench).
- also change the default draft angle from 1.5° to more common 10° and the step to 1° so that one can quickly get usual angles for drafts
