Fizik/general BOA fine tuning question

[Robbos]

I'm currently on a pair of Fizik Vento X3's, which I really like- light, stiff, great-ish fit, etc. I wondered whether a simple BOA, unlike the double on the pair of Shimano XC702's I was eyeing around the same time, would do. And it does-sort of. I find it hard to get the right amount of tension in the lower section- further forward on my feet, when it's already getting snug up by the BOA. What are other peoples experiences?
I saw this hack on Bike Rumor and it intrigued me, I may just try it. Thoughts?