I think the premise is to be able to make the entire kit at will from whatever you find. That is what I was taught, and that's how I do it. With that said, there is no cheating when it comes to wilderness survival. As a matter of fact, the very idea of wilderness survival depends on the most amount of work with the least effort. Use whatever you can to gain the upper hand.
Making a bearing block takes very little time in the grand scheme of things, I can make a working bow drill set, from 1 piece of wood, in about 20 mins, hearth, spindle, bearing block and bow. I use paracord, mainly because I always have some with me, and I'm not that good at making good cordage. So I use paracord, big deal, I wear a para bracelet at all times, I have para on everyknife I own, and its stuffed away in every bag, and coat pocket I own. Chances of me being without paracord is slim to none.
I like the idea, and I am going to look into putting a skateboard bearing onto one of my knife sheaths, so I can try it out. They put divots in micarta handles on knives, and at least this way, you don't have a knife edge to worry about.
Like I always say, learn the skill, then learn how to make it faster, better, and easier to do. No shortcuts or cheating there, just good sense.
Moose