Matt
I am trying to work out what you are asking for here.
Currently you can select any number of linestrings graphically and in the properties pane you can override the segment length on all the elected lines in one pass and change the value to a common value.
If each line needs a separate value then change the flag on all the lines to the Override, and then select each line in turn after setting the override and enter its own value
If each line you select has to have a different override length then you can also pick lines one at a time and override the length with different values.
The value you enter in the override is a Max value so for example if you have line segments of a single line of 6m, 7m, 8m, 9m, 10m in length then in those segments, when you apply a max value of 2 then in the first segment the divisor will be 2, in the second line it will be 1.75, then 2 then 1.8 then 2 etc. so it is dividing each segment of the line into approximately equal lengths based on the length of the segment and the max length override that you enter - so entering a value of divisors over the entire length of the line would not work today because the divisor is computed on each segment (and this is likely the right way to do this as all segments will be variable length), and for sure on curves you want to use Arc to chord to compute those.
What would an extra command do that you cannot do with the properties pane already?
Are you asking to be able to effectively "divide line" by looking at the length of the line and dividing it into a number of segments (for model purposes only) where the length of each segment is Length of line / number of segments and set that as the override length value?
If yes, can you explain when that approach is more useful than just entering a value for the segment length?
This should likely only really affect long straight segments of a line anyway as the horizontal and vertical tolerance setting (in project settings) should take care of all the Hz and Vt curve sections of a linestring in the model.
Alan