I looked up info about EC-1118 because of something I read in another thread, and found the Lallemand page:
https://www.lallemandbrewing.com/en/united-states/product-details/lalvin-ec-1118/
Note that in section Oenological Properties, it reads: Competitive killer factor: yes
Folks have posted that some kits include packets of EC-1118 plus another yeast, with the intention that both are used. It appears that co-inoculating with EC-1118 is a waste of yeast, as it's likely to kill all competitors. If I purchased a kit with 2 yeasts, I'd not use the EC-1118 unless the ferment stuck.
https://www.lallemandbrewing.com/en/united-states/product-details/lalvin-ec-1118/
Note that in section Oenological Properties, it reads: Competitive killer factor: yes
Folks have posted that some kits include packets of EC-1118 plus another yeast, with the intention that both are used. It appears that co-inoculating with EC-1118 is a waste of yeast, as it's likely to kill all competitors. If I purchased a kit with 2 yeasts, I'd not use the EC-1118 unless the ferment stuck.