Default auto-leading, based on the current type size is supported in GN4 from the version 2.3.
To set/change the Auto-leading preference
1.While editing text, on the Edit menu, click Preferences, and then on the General tab, locate the Auto-leading setting.
2.Tick the Auto leading to enable the functionality.
3.Enter the leading percentage you want, such as;
o100% to make the leading equal to the type size
o101% or greater to have the leading greater than type size
o99% or smaller to have the leading smaller than type size
4.Click OK to save the preference and close the dialog box.
Note
The allowed range of auto-leading percentages is 0% - 500%, but the effects may be rather weird. It is recommended the use the range between 70-200% instead.