I think I am tracking where BADFNZ is coming from. The ultimate goal of a promotion board is to select individuals who show the potential to excel at the next rank, which is why a SR may elect to leave off some strats if they are heavily weighted towards a lack of breadth. For example, we all agree on this forum that being an expert in your airframe should be a top priority but a PRF that is overwhelming geared towards flying strats (#1/69 IPs, Top 10% ACs, etc) would not "look" appealing to a promotion board that is looking for an officer with future leadership potential (don't hate the player, hate the game). That thought process is why I have seen "decent" strats left off (assuming there is a decent size pool to choose from) to include a lesser strat of a different category or even a strong bullet that highlights FGO potential (lead team of SARM NCOs through MAJCOM inspection over #1/15 Flight Leads from an OPR 3 cycles ago). Of course, if all the strats are #1 type strats it would be hard to argue leaving them off. The PRF also has limited space to relay the SRs message so filling it with "soft" starts may look more like a way of masking a perceived weakness or lack of breadth.
Although determining school selects is not a separate process but a function of taking a slice off the top XX% of the PRFs, a SR could certainly shift focus on a PRF when compared to an individual he/she may be more concerned about simply making the promotion list. I would imagine an individual a SR wants to get promoted but their record isn't great would prioritize grabbing everything remotely positive when compared to an individual the SR is trying to push for school via the promotion board. That person's PRF would probably have some decent bullets/strats left off in order to present the "big picture" of someone who is primed for leadership (more whole person compared to the greatest IP I have ever seen). Although most of us would prefer to have the greatest IP promoted it is not how the system works. So this is why the SR is making the PRF look the best it can, but what is best for one person is not the best for another.