Kanji vs. Kana: Balancing Efficiency in Rapid Writing

When taking notes during a lecture, I often struggle to find the right 表記 balance. Using kanji for words like 防ぐ can definitely clarify meaning, but I worry about the time spent on stroke count. How do 皆 determine the threshold where a complex kanji becomes a hindrance? I am trying to develop a system that maintains legibility without sacrificing speed.