The new 'Duplicate as' feature in Max begs for one little thing more. Now we can duplicate or convert a line into a Length measurement including all visual properties corresponding to what has been set via 'Set as Default'. Very handy! The major thing missing there is the Subject. Actually this should also be a setting in the Format Painter. I suggest, when upgrading, to rename it to 'Property Painter'. In the Preferences there should be a page with checkboxes for configuring which properties to copy along while duplicating, converting or painting.
P.S. Start and End arrows of a Polylength do come along with the Format Painter, but they don't with the Convert to. Also: converting a single line to a Length doesn't produce the text showing the length, which works fine when converting polylines to polylenghts.