This post is old, but I can make an update.
And I was wondering, but it seem's that no one in Google Group or on Slack speak about https://n8n.io/
Jan (the founder of N8N) did win a battle as he succeed to make it as a selling product.
And it seem's working as now N8N project is stared 17k on Github : https://github.com/n8n-io/n8n
. And the project continue to growth.
Compared to FBP, this seem's very similar.
I think Jan focused more on making the product work, and adapted to his need.
As N8N don't seem's to follows FBP format, N8N seem's to get it's own that look like FBP format. But may be by the time it will (I have no clue on the roadmap for that point)