To get SLM or not?

I have been focusing on having 2, sometimes 3 labs running econ. Slowly getting closer to max GT labs and BH coin. I am lv8 lab with SL coin bonus, hoping it will help some for econ.

Current UW's are only SL, GT, BH.

Wondering if getting SLM would help increase coin gain for SL? I only have one angle so far, not much has been put into it. My SL only accounts for maybe 5% of total coin gain in a run.