While a certain degree of structure is needed in any collective prayer, there is always a danger that it becomes too mechanical and rigid and starts losing its purpose. An individual may find certain ritualistic acts consistent with his spiritual aspiration if they fulfill an inner need for connecting outwardly with the Divine whom he inwardly adores. But this must be determined from within as a spontaneous urge and need of the inner being and not through outer mechanical means proscribed by someone. This happens in religions but in spirituality it has very little place beyond maintaining a group discipline. Each one is best left free to invoke in their own way even though the time can be fixed for a collective prayer. It is the central aspiration that is much more important than words repeated mechanically and too often whence they begin to lose their value.
Perhaps when those who are part of a group have trust in the leader, the structured collective prayer may work. But in general such things tend to turn a spiritual movement into a religious one from which truth tends to escape into the secrecy of its silence. By its nature spirituality is something that is too vast and plastic, which is why perhaps the human mind, limited and accustomed to live within boundaries is unable to handle it. It feels much more comfortable to turn it into rigid formal methods. Besides some kind of an external ritual, such as lighting the agarbatti etc. is much easier than turning within.
Unfortunately the fate of most spiritual truths is that over a period of time the outer shell remains while the inner is gone or even occupied by all kinds of entities that have little to do with their truth. The Mother knew about this tendency to turn everything into a religion, including Sri Aurobindo’s yoga, and cautioned about it but also said that this will not happen here. It is best to leave it at that and let everyone and every group follow their own way of relating and connecting with the Divine. When the time comes, She will show its inadequacy and the change will come automatically from within.