I’m honestly not surprised that he hasn’t found any substantially well-done research pointing to compost tea benefits.
While I admit I’ve never been hellbent on making or using compost tea, I can quickly understand why there’s so many variables involved to create effective tea.
Compost itself has sufficient beneficial microbes to give plants what they need.
It seems to me that it’s too easy to create compost tea that’s overpowering and can actually harm your plants.
At the same time, if you’re simply adding FINISHED compost to a bucket, adding water, stirring it and adding it to your plants, I don’t see the harm in that.
It appears to be a common mistake to use compost leachate as tea, which obviously is a complete risk since it’s not liquid resulting from actual compost but from material going through decomposition.