It could be, but you can always reuse the mapping result for many subsequent attacks without losing that much accuracy. IP addresses will drift due to reassignm

It could be, but you can always reuse the mapping result for many subsequent attacks without losing that much accuracy. IP addresses will drift due to reassignments over time, but I can easily see a map remain usable for a week or a month. You could also just sell/buy it from someone else, which costs less.