Indeed, Hutchings recommends frequent agitation verging on constant. Semi-stand seems to go against its prescribed advice that it must be used immediately. All I can say is that if left to sit in a tray (sheet) in the as brief as practical time it takes from mixing (one shot) through presoak (at least +2.5 minutes) to immersion, the solution begins to separate, no matter how well mixed. I agitate the developer even before I drop the sheets in, thence every 5 seconds to constant for consistent results.
To the OP, I think if pragmatism is your goal, you're better served to search out the many posts for empirical use of PMK. Even though I have a signed and dedicated book, which I'm not selling, I have found its approach to be fairly didactic and thesis like, its main use being introductory use of the developer.