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?

[rice rocket]

I've never seen that hack and would be hesitant to tie knots in tension cables, but my Shimano shoes have an extra channel for you to loop the cable, expressly for that purpose.