Why do you need so much precision in your dimension lines ? Tolerances in the building world are generally quite high.
Anyway, if you didn’t notice yet, the precision of the dimension lines depends on the current zoom factor, so zoom in more to get more decimals. Note also that double clicking along walls, room sides or furniture sides will automatically create a dimension line when the tool is activated.
like anyone else, i would just find some other software […]
Do you really think that this kind of comment will make the community want to help you? 
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Emmanuel Puybaret, Sweet Home 3D creator
