Ahhh ... I don't do nothin! Just mix, pour and let it sit! Sans semi, so to speak.
But! ... sometimes I do a little less or a little more depending on the light, etcetera.
All of that said, I'm not convinced i've reached the perfect recipe just yet ... it's just been working well enough that I don't have to work too hard in the darkroom to get good prints.
But an hour difference for the same rating makes me wonder what I might be doing wrong —or could be doing better —and in less time!
One thing is: I do not soak the film before developing, which is what that recipe you linked, called for.
This is just more evidence of the fact that stand development is something that has to be honed by each individual to his/her taste and preference. All of this is just a starting point.