1st solo
The first solo is indeed a great confidence booster but that is not to say it is of any value in the outcome of the training. The benefit of an early first solo is exaggerated. More commonly it is a negative pressure on a student to achieve an early solo in line with a norm (sic). Often the first solo offers an opportunity of snobbery in the clubhouse, "how many hours did you have before your first solo?".
A concept that a student (6,7, 10-12 hours to solo which has been often boasted on this forum as if it meant anything much.) is better for going solo very early is nonsense. I am becoming convinced that there is no need for a PIC demonstration until the full syllabus has been comprehensively covered and the student has the gained ALL the skills required to undertake the roll of acting in COMMAND of the aeroplane.