When taking off quantities in lengths i prefer to use m rather than mm. Is there a way to set this as the default for all my take offs
It's not obvious, but it is possible. When you make a measurement, go to properties and change the unit to 'm'. I'm sure this is very familiar to you:
Next, go back to your measurement and right click and then select, set as default.
You'll need to do this for each measurement tool, make one measurement, change the properties to what you want and then set as default.