Disclaimer: These tips are for the blog author, pls seek professional instruction as this sport may be dangerous!
Lower is better than higher. By far!
After the conversation with Drew from Different Bikes I realized that the lower stem makes it for much much better steering control, body position and overall riding.
It is simple to "hunt for" the sweet spot: no cutting of anything is needed. I simply took a big fat spacer from the bottom and put it on top of the stem!
I was amazed what a couple of mm do in this context, it may as well be miles of distance for a bike-less-self-propelling individual in a totally different context.
And yes, I made sure that all the bolts are tight when I was done: I first loaded the star nut and then tightened the stem bolts, not the other way around!