drilling 戦時 in phase 4 without losing 0.5 percent retention

I hit hour 712 of my vocabulary grind and 戦時 kept dropping my daily retention rate to 88.5%. To fix this without wasting active recall slots, I set up a 3-step micro-drill. Step one: isolate the Kanji in 10-minute blocks. Step two: batch it with context words like 協力 and 断念 to force thematic neural pathways. Step three: run 15-second hyper-spaced repetitions at exactly 08:00 and 20:00. Purely mechanical.