I could, theoretically, see rustroot (perc*explo>=400, I have 30 explo and 16 perc due to I KEEP LOSING TRACK OF MY stuff and I also keep getting int when I have like 20 perc and 1.2 int on a 20.2 FEP scale)
E. Dit: that's @ the whole cavebulb discussion. no concrete numbers for cavebulbs though