John, I don't know that I have an answer that is current to your question about the economics of Lilac's lithium extraction, but I have come across some information re: the history of Lilac and some of that information addresses costs of production based on Phase 1 Engineering Study results at Kachi Lithium Brine Project in Argentina.  Links provided below:

https://ideas.northwestern.edu/projects/lilac-solutions.html

"Phase 1 Engineering Study shows potential for lithium production costs to be US$2,600/tonne (+/-30%) in lowest quartile at Lake Resources’s 100% owned Kachi Lithium Brine Project in Argentina, using Lilac’s direct extraction process."

http://www.lilacsolutions.com/news/lake-resources-lilac-solutions-press-release-dec2018

"The study also showed that the process offers the potential for a globally-competitive cost of production, estimated to be US$2600/tonne (+/-30%) in the lowest cost quartile for lithium carbonate production. (Note: The estimated costs of production are preliminary estimates based on the Phase 1 Engineering study.) "