> freelancer can work on it in confidence
Mm, that is different for copy-editing, which is what I do: I need to share what I am doing as I go along. OK, escrow looks a better fit.
> Escrow.com looks ok - except that it's in the US and I didn't see anything for freelancers
The category is "contracted services": see https://www.escrow.com/learn-more/how-escrow-works/professio...
They allow contracts to be denominated in Euros.
> But there may be those motivated by something I can offer - like a discount? fun with new tech? granular control of acceptance & payment?
Ah! Yes, I guess there are people in the smart contracts crowd who would be interested in talking. Since your story didn't get very far here, maybe Twitter is a better avenue?