Hello,
Taking into account Units in questions is very useful. Tell me if I'm wrong, but there is currently no possible affine unit conversion in addition to proportionnal conversion already existing. As an exemple, for temperatures, conversion between kelvins and Celsius degrees (+/- 273.15) does not seem to be currently supported by Moodle (version 3.x in use), yet that would be quite useful.
I'm looking forward to see this improved functionnality...
Best,
Sylvain