[RedBaron]

As far as I know, Amano uses substrate as the main source o nutrients. So if you pull off the plant you cut off the access to these nutrients.
Secondly, trimming is less time consuming and it allows to control precise shape of the plans.
But it's only my opinion :lol:

 

[RedBaron]

Mr. Amano visited my country recently, he told that as long the substrate is reach with nutrients it should be should be considered as a main source. It's obvious that with time such substrate loses its properties and additional liquid fertilizers should be added.