Heeey that chracter study looks REALLY good! Keep it up!
Don't worry about the pace, we each eventually follow the pace and the companion guide in whichever way best works for us. Ideally you want to follow and do as much as possible, but sometimes we simply don't have enough bandwith and will tweak the tasks to fit within our bandwith.
Personally, I also can't follow the guide as faithfully as possible, so instead I go through it as if it was a checklist, making sure at the very least I perform the exercices mentioned without any real timeframe limit, understanding the objective of each task mentioned. I'll usually also add a few more points to each exercice to get the most out of it, for example, practicing inking, a specific style, character desgin, adding perspective, etc. Seems to work out well so far.