I think the wide variety of opinions on inflow/outflow placement can be credited to the fact that ideal placement is arrangement-dependent. For example, are you going to have a concave, with dense planting at the left and right rear corners and lower plants along the center and front, with open water space in the center? Your inflows and outflows may need to be placed in a particular arrangement for that. Now, what if you go with a triangle scape? You may want to arrange your inflow/outflow a little differently for that. What if you go with tall stems along the back? You don't want to blow them all over the place. What if you go for a landscape layout with foreground plants almost exclusively? Now, you have the entire top half of the water to churn as much as you want.
Since the layout of the hardscape, robustness or delicateness of the plants, and height of the plants can dictate how much current is adequate and where that current needs to run, I'm not sure there is a general consensus on inflow/outflow placement. People generally agree to disagree because each person is forming his or her opinion based on the needs of his or her own aquarium.
If you change your mind a lot or just like to experiment with different layouts, I would recommend avoiding any modifications to the tank that can't be undone.
I'm not trying to sidetrack your thread or change the subject, I just want to be sure that the dynamic nature of planted aquariums is mentioned before taking any single point of advice for drilling. Good luck!
"Insanity: doing [or asking] the same thing over and over again and expecting different results."