Great idea about mapping the seedling tray. I had not thought of that one. I have a few seedlings with a similar story to yours. That is when I decided to map them. Dang crows removed fully half of my labels one year. Luckily that year was mostly dogs so most were compost. Only have 1 or 2 left from that mess.
It's my cats world, I'm just here to open the cans.