Increase log2timeline processes for plaso ingest?

I’m currently running the plaso ingest module against an image and I notice that it only uses 3 log2timeline processes. I have plenty of memory still available and my disks are all sitting at effectively 0% usage, but the log2timeline processes are maxing out the cpu core they’re using. So it seems as though the CPU is the bottleneck in this situation. Is it possible to increase the number of log2timeline processes or is there a specific reason it’s only 3?