Id say no. Well over 99% of mono tracks can be stealthed by a strong player on the first run, with clean finish added on the second, because the execution required to do so is minimal and the strategy needed is generally nonexistant. The other 1% of tracks (mostly those with very high traffic or unusual traffic / track layouts) may merit some consideration, perhaps in the form of a dynamic stealth bonus that increases sharply as a traffic~time equation exceeds a certain threshold, or some skill intensive way to hold chain across the vast seas of grays that often occur in such tracks, but just granting mono a greatly increased scoring potential with minimal risk or skill required is a terrible idea.
Youll hear the top puzzle players claim that mono is the easiest mode, and with the 1% killer track exception mentioned above withstanding, they are correct. Consider that the most (over)played competitive song, TTFAF, is still seeing noticable top puzzle mode score increases some 2 years after the games release. Now also consider that the top possible mono scores (top as in, the max- theres zero room for further improvement) were likely all posted on that first day... i hope you get the picture.
Mono-only boards are available, btw. You can access them by clicking on one of the mono symbols at the bottom of the main online scoreboard.