Question about vpd number

So a quick question, All the VPD charts and everything that I have collectively read says that you want to stay in the middle of the green highlighedpart if possible.
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So here comes my concern, a lot of the charts with everything I’ve read and seen stay at about 1.3 compared to the 1.5.
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Was just wondering people’s thoughts.

1.2 kPa is closer to the ideal, but it’s hard to keep RH low in late flower, while still hitting a decent temperature, so it’s okay to creep up to 1.5kPa towards late flower.