Just to add, many plants do have a "preffered" method of nutrient source which can effect the growth rate and overall look of the same plant.
For instance you mentioned Java Ferns... they do feed through their roots also and they
will root in substrate if givin the chance but the plant seems to lose growth rate when too much of its roots are not freely available to the water column. I have found that they actually get a growth burst when the roots are trimmed occasionally. This is why you see most of the ferns strapped to wood or stone, the roots will rot if they get buried or get to thickly piled and it effects growth.
The same applies to say swords, only reversed, they will grow
without being in a good nutrient rich substrate but they will not compare in growth to those that are buried and well fed.
Generally, you can tell just by looking at a plants root system to tell which they prefer... if they are hairlike roots , they are more for holding a plant in place rather then feeding and will enjoy a nutrient rich water column but if the roots are larger like crypts,swords, anubias etc. then its a good chance it "prefers" to fed through the substrate.
Of course thats not exact science , just an opinion.... :lol: