Just seeing this independent thread on Clops and this newbie! Going to read through in just a little bit. I have not seen something just like the new one. But I did lots of research about chick eye issues when I had mine this summer, and, it's usually an issue of nutrition in the breeder flock, egg storage (cold/heat mostly), or incubation. You incubate enough of your own chicks to know that we can likely take the last one off. We probably won't really ever know the cause. I normally say I wouldn't order or hatch eggs outside of my own in August/January, but, I did both this year. ¯\_(ツ)_/¯
I see, sometimes, that you are getting a little overwhelmed and just wanted to offer thoughts, for whatever they're worth, to hopefully provide comfort in the midst of the stress. Chicken keeping is highly personal. Personal philosophies, personal beliefs about animals, livestock, food, etc. Most advice is based on anecdotal evidence. So many things about every aspect of chicken keeping change from person to person and environment to environment. Gather all the information that you can, and make informed decisions. Some will be right, some may not be, but you learn and improve and build more knowledge for your specific case of circumstances. You're doing great. Whatever you ultimately do will be what is best for your situation. I personally believe we are always right where we are supposed to be.
I have the hardest time culling chicks over anything else. Taking quality of life into play, and my own capacities for the rest of my responsibilities, I see absolutely no reason not to try and provide a life for one if you can make the accommodations work. I'd make a pretty horrible breeder with these sensibilities, so, I'll leave that to others. ;-)
I think I follow a blind chicken on FB. Are you on Facebook? Im going to see if I can find something outside of FB. I feel like I saw you say sometime you weren't on FB.