Dahon is the biggest folding bike company in the world. I doubt they would be very interested. Contact Thor to see the level of interest.
Tern doesn't have a good reputation here....so I wouldn't try. Trust me on this one
I don't see Pingis doing this. I would be doubtful of Euromini....they are new to the industry, and I don't see them staying in long term. They entered the market about a year ago & they sell non bike products from the same warehouse. Feels sketchy to me.
Bike Friday is in need of a new product. They are a great company. I would recommend you contact them.
Otherwise a user here is an IP attorney. I recall his username is something like Manakea. He's in Hawaii and maybe a good partner.
Thanks
Yan