Originally Posted by
cyccommute
It will work fine.
+1. Road front derailleurs work remarkably well with MTB cranks and their "too small" chainrings.
My son's '98 Trek 1220 came factory stock with an RSX triple crank with 46/36/26 chainrings and an RX-100 road front derailleur intended for a 52T big chainring and it shifted (and still does) very well.