As for an ALO "Bragging up" a candidate, that's kind of an iffy statement. There are many hundreds of ALO's in the country/world. Almost none/never does the ALO speak with members of the selection board. We/They do speak with the admissions office, but they (The admissions office) doesn't decide who receives an appointment. They ensure that the application/package is complete, qualified and accurate. If it's not, the package won't even get reviewed by the selection board. We/They ALO's do on our interviews, have a form that is filled out. It covers many areas of the individual. Leadership, values, morals, judgement, motivation, initiative, relationships, etc. We fill this information out, in a limited number of words/sentences; and we also give each area a numerical score. This is what the review selection board sees. This is the only place that an ALO can really "Brag Up" an applicant. The review/selection board also knows that every ALO wants THEIR applicants to get an appointment. Therefor, they know that we're going to "Brag Up" most of our applicants that we interview and submit.
Not saying that an ALO can't help get some extra points in the overall application score. But considering, that an ALO let's say has 10 applicants that they are reviewing and scoring. All ten might have numerical scores spanning 20 points. There might be a few low scores and keeps the individuals from being competitive; but those that the ALO believes to be competitive and should be considered for an appointment, are probably all pretty close to each other in scores. That's why the percentage isn't what you'd imagine it to be. Another way of saying this is; when you consider that the average GPA of the 1200+/- appointees is a 3.86, and the ranges is all close to each other; imagine the same for all the appointees ALO reviews and scores. They all probably are within a few points of each other.
That's why I say, that an ALO really can't help much on getting an individual an appointment; but they definitely can make it so an individual DOESN'T get an appointment.