People on reddit anyhow think the Flux.dev model can be used for commercial purposes.
Here is my understanding.
From the flux-dev license page,
“Non-Commercial Purpose” means any of the following uses, but only so far as you do not receive any direct or indirect payment arising from the use of the model or its output: ...
Just replace the capitalised words (Non-Commercial Purpose) with the entire definition.
Non-Commercial Use Only. You may only access, use, Distribute, or creative Derivatives of or the FLUX.1 [dev] Model or Derivatives for any of the following uses, but only so far as you do not receive any direct or indirect payment arising from the use of the model or its output.
You may use Output for any purpose (including for commercial purposes), except as expressly prohibited herein.
So it is actually prohibited if I re-read the above portion on Non-Commercial Use Only.
I am very certain only the outputs from the Pro version can be used commercially.
The Dev version is for development usages, such as an artist using the output-image for rotoscoping of a character in a specific pose. In other words, it is meant to increase an artist's productivity. And the output-images are not used directly in the final product.
See what the authors over at Black Forest Labs reply.