personally, every time ive had plants that small at 2 weeks theyve continued to be slow and ive ended up axing them. Imo they are either weak beans, struggling with the mediums ec or ph, or are naturally very slow growing.
You just have to ask yourself is it worth another 6 to 8 weeks of your time to grow them out and possibly come good or find out that they remain stunted and poor growing . ..when you could pop a few more beans and find something that grows a lot better.
Its ok saying give them time, but seedlings are usually a good bit further on at 2 weeks