I'd use the advice already given and if it produces negs with good shadow and highlight detail and the prints are fine somewhere between grade 2-3 then I'd conclude that you have got it right.

On the other hand when people give advice that basically says: "leave well alone" the human psyche often want to see if the advice is optimal or if some development change might improve things.

If you are left with nagging doubts then you might try progressive reductions of initially 10% in development time to see if there is any substantial improvement. This will be a win/win outcome in the sense that if less development is in fact a lesser option it won't enough to ruin the negs which should still print OK.

pentaxuser